JavaScript Essential exercise for Beginners

JavaScript exercise/examples for Beginners

01. What is JavaScript?

JavaScript is a programming language that adds interactivity to Web pages
JavaScript is a scripting language
A JavaScript script is a program that is included on an HTML page
JavaScript scripts are text on Web pages that are interpreted and run by Web browsers
JavaScript is initially named and developed as LiveScript at Netscape Navigator Corporation
JavaScript is not Java
Due to Java wave or Java popularity and buzz, LiveScript renamed to JavaScript

02. What can JavaScript do?

Create an active User Interface
Control the user experience based on Day, Date, Time and Browser, etc
Validate user input on forms
Create custom HTML pages on the fly/dynamically
Control Web browsers interactivity and behaviors

03. What can't JavaScript do?

JavaScript can't talk to a Database (Its possible with NodeJs)
JavaScript can't write to files (Its possible with NodeJs)
Keep track of state (except with cookies)

Topics include

Example 1 - swapping variables
Example 2 - max number
Example 3 - Landscape Portrait
Example 4 - FizzBuzz Algorithms
Example 5 - Speed Limits
Example 6 - Odd Even Number Loop
Example 7 - Count Truthy Falsy Values
Example 8 - Object String Properties Key
Example 9 - Sum of Multiples
Example 10 - Netsted Loop Star Pattern
Example 11 - Marks Average Grade
Example 12 - Random Bingo Card
Example 13 - Show Prime Numbers
Example 14 - Sum Of Arguments
Example 15 - Sum Of Arguments Array
Example 16 - Circle Area Object Read Only Property
Example 17 - Create Array From Argument Range
Example 18 - Array Includes Element Exists
Example 19 - Array Excludes Value To New Array
Example 20 - Array Count Search Occurances
Example 21 - Array Get Max Largest Number
Example 22 - Array Filter Sort Map
Example 23 - Object Create Students and Address Object
Example 24 - Object Create Object Factory Constructor Function
Example 25 - Object Equality

Example 1 swapping variables

Image 1 - Swapping Variables

Syntax & Example: 1-swapping-variables.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>swapping-variables</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>1-swapping-variables!</h1>

  <h3>Swap the values of variable</h3>
  
  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('1-swapping-variables');

let value1 = 'one';
let value2 = 'two';

// original values
console.log('original', value1);
console.log('original', value2);

// swapping values
let value3 = value1;
value1 = value2;
value2 = value3;

console.log('swap', value1);
console.log('swap', value2);

Syntax & Example: global style.css

body{
  font-family: 'Lucida Sans', 'Lucida Sans Regular', 'Lucida Grande', 'Lucida Sans Unicode', Geneva, Verdana, sans-serif;
}

h1, th{
  font-family: 'Trebuchet MS', 'Lucida Sans Unicode', 'Lucida Grande', 'Lucida Sans', Arial, sans-serif;
}

table{
  /* border: 2px solid #696969;
  border-collapse: collapse; */
  font-size: 18px;
}

th{
  width: 20%;
}

th, td{
  padding: 10px;
  border: 2px solid #696969;
  text-align: center;
}

#freeSquare{
  background-color: coral;
}

Example 2 max number

Image 2 - Max Number

Syntax & Example: 2-max-number.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>max-number</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>2-max-number!</h1>

  <h3>Write a function which returns the maximum of two number</h3>
  
  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('2-max-number');

function findMaxNumber(num1, num2){
  // 1. long syntax
  /* if(num1 > num2){
    return num1
  } else {
    return num2
  } */

  // 2. short syntax
  /* if(num1 > num2) return num1;
  else return num2; */

  // 3. ternary short syntax
  return (num1 > num2) ? num1 : num2;
}

let checkMax1 = findMaxNumber(10, 5);
console.log('Max Number:',checkMax1);

let checkMax2 = findMaxNumber(10, 15);
console.log('Max Number:',checkMax2);

let checkMax3 = findMaxNumber(100, 100);
console.log('Max Number:',checkMax3);

Example 3 Landscape Portrait

Image 3 - Landscape Portrait

Syntax & Example: 3-landscape-portrait.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>landscape-portrait</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>3-landscape-portrait!</h1>

  <h3>Write a function which checks given width and height, returns true (landscape) if width is greater than height and vice versa</h3>
  
  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('3-landscape-portrait');

function isLandscape(width, height){
  // 3. ternary short syntax
  return (width > height);
}

let checkWidthHeight1 = isLandscape(800, 600);
console.log('Landscape:',checkWidthHeight1);

let checkWidthHeight2 = isLandscape(600, 800);
console.log('Landscape:',checkWidthHeight2);

let checkWidthHeight3 = isLandscape(1024, 768);
console.log('Landscape:',checkWidthHeight3);

Example 4 FizzBuzz Algorithms

Image 4 - Ffizzbuz Algorithms

Syntax & Example: 4-fizzbuzz-algorithms.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>fizzbuzz-algorithms</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>4-fizzbuzz-algorithms!</h1>

  <h3>Write a function which checks given input/parameter:</h3>
  
  <ul>
    <li>If input/parameter is divisible by 3 print => Fizz</li>
    <li>If input/parameter is divisible by 5 print => Buzz</li>
    <li>If input/parameter is divisible by 3 or 5 print => FizzBuzz</li>
    <li>If input/parameter is NOT divisible by 3 or 5 print => given Input Number/Value</li>
    <li>If input/parameter is other than Number/Value print => 'Nan - Not a Number! Please Input Number' </li>
  </ul>
  
  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('4-fizzbuzz-algorithms');

/* 
<h3>Write a function which checks given input/parameter:</h3>

<ul>
  <li>If input/parameter is divisible by 3 print => Fizz</li>
  <li>If input/parameter is divisible by 5 print => Buzz</li>
  <li>If input/parameter is divisible by 3 or 5 print => FizzBuzz</li>
  <li>If input/parameter is NOT divisible by 3 or 5 print => given Input Number/Value</li>
  <li>If input/parameter is other than Number/Value print => 'Nan - Not a Number! Please Input Number' </li>
</ul>
*/

function isfizzBuzz(arg){
  if(typeof arg !== 'number'){
    return ('Nan - Not a Number! Please Input Number');
  }

  if((arg % 3 === 0) && (arg % 5 === 0)) {
    return 'FizzBuzz';
  }

  if(arg % 3 === 0) {
    return 'Fizz';
  }

  if(arg % 5 === 0) {
    return 'Buzz';
  }

  else {
    return 'Some odd number entered: ' + arg;
  }

}

let checkFizzBuzz1 = isfizzBuzz('one');
console.log(checkFizzBuzz1);

let checkFizzBuzz2 = isfizzBuzz(true);
console.log(checkFizzBuzz2);

let checkFizzBuzz3 = isfizzBuzz(9);
console.log(checkFizzBuzz3);

let checkFizzBuzz4 = isfizzBuzz(10);
console.log(checkFizzBuzz4);

let checkFizzBuzz5 = isfizzBuzz(30);
console.log(checkFizzBuzz5);

let checkFizzBuzz6 = isfizzBuzz(11);
console.log(checkFizzBuzz6);

Example 5 Speed Limits

Image 5 - Speed Limits

Syntax & Example: 5-speed-limits.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>speed-limits</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>5-speed-limits!</h1>

  <h3>Write a function which checks given input/parameter:</h3>
  
  <ul>
    <li>If input/parameter is below speedlimit of 70 print => 'Good Safe Driving'</li>
    <li>If input/parameter is above speedlimit of 70, every 5 kilometers is Penalty Point, print => 'Speed Limit Crossed by Penalty Point' + Point </li>
    <li>If Driver gets more than 10 penalty points ie. above the speed limit 120, print => 'License Suspended'</li>
  </ul>
  
  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('5-speed-limits');

/* 
<h3>Write a function which checks given input/parameter:</h3>
  
<ul>
  <li>If input/parameter is below speedlimit of 70 print => 'Good Safe Driving'</li>
  <li>If input/parameter is above speedlimit of 70, every 5 kilometers is Penalty Point, print => 'Speed Limit Crossed by Penalty Point' + Point </li>
  <li>If Driver gets more than 10 penalty points ie. above the speed limit 120, print => 'License Suspended'</li>
</ul>
*/

const SPEEDLIMIT = 70;
const KMPERPOINT = 5;

function checkSpeedLimit(curSpeed) {
  if (curSpeed <= SPEEDLIMIT) {
    return ('Good Safe Driving!');
  } else {
    let penaltyPoint = Math.floor((curSpeed - SPEEDLIMIT) / KMPERPOINT);
    if (penaltyPoint < 10) {
      return ('Speed Limit Crossed by Penalty Point: ' + penaltyPoint);
    } else {
      return ('License Suspended!');
    }
  }
}

let checkPoin1 = checkSpeedLimit(40);
console.log(checkPoin1);

let checkPoin2 = checkSpeedLimit(70);
console.log(checkPoin2);

let checkPoin3 = checkSpeedLimit(75);
console.log(checkPoin3);

let checkPoin4 = checkSpeedLimit(99);
console.log(checkPoin4);

let checkPoin5 = checkSpeedLimit(120);
console.log(checkPoin5);

Example 6 Odd Even Number Loop

Image 6 - Odd Even Number Loop

Syntax & Example: 6-odd-even-number-loop.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>odd-even-number-loop</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>6-odd-even-number-loop!</h1>

  <h3>Write a function which checks number till given input/parameter is odd or even</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('6-odd-even-number-loop');

function isOddEvenNumber(curLimit) {
  for(let i = 0; i <= curLimit; i++) {
    /* if (i % 2 === 0) {
      console.log(i , 'EVEN');
    } else {
      console.log(i , 'ODD');
    } */

    const alertMessage = (i % 2 === 0) ? 'EVEN' : 'ODD';
    console.log(i , alertMessage);
  }
}

isOddEvenNumber(10);
// isOddEvenNumber(17);

Example 7 Count Truthy Falsy Values

Image 7 - Count Truthy Falsy Values

Syntax & Example: 7-count-truthy-falsy-values.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>count-truthy-falsy-values.html</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>7-count-truthy-falsy-values!</h1>

  <h3>Write a function which checks and count the truthy values from an array</h3>

  Falsy values in JavaScript are:
  <ul>
    <li>false</li>
    <li>0 (zero)</li>
    <li>undefined</li>
    <li>null</li>
    <li>''</li>
    <li>NaN</li>
  </ul>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('7-count-truthy-falsy-values');

/*
<h3>Write a function which checks and count the truthy values from an array</h3>

Falsy values in JavaScript are:
<ul>
  <li>false</li>
  <li>0 (zero)</li>
  <li>undefined</li>
  <li>null</li>
  <li>''</li>
  <li>NaN</li>
</ul>
*/

const valuesArray = [0, 1, '', undefined, false, true];

function checkCountTruthyFalsy(curArray) {
  let truthyCount = 0;
  
  for (let value of curArray) {
    // no need to check if(value !== false || value !== 0 || value !== '' or ...)
    if (value) {
      truthyCount++;
    }
  }
  return truthyCount;
}

console.log(checkCountTruthyFalsy(valuesArray));

Example 8 Object String Properties Key

Image 8 - Object String Properties Key

Syntax & Example: 8-object-string-properties-key.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>object-string-properties-key</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>8-object-string-properties-key!</h1>

  <h3>Write a function which checks and prints only the string type properties of an object</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('8-object-string-properties-key');

function showStringProperties(curObj) {
  for(let key in curObj) {
    // console.log('key/prop:', key);
    if(typeof(curObj[key]) === 'string') {
      console.log(key,':', curObj[key]);
    }
  }
}

const Person = {
  name: 'Dinanath',
  age: 40,
  height: 5.6,
  country: 'India',
  designation: 'UI Developer'
}

showStringProperties(Person);
console.log('----------');

const Technology = {
  name: 'JavaScipt',
  version: 6,
  purpose: 'Scripting language for Web',
  developer: 'Netscape Corporation'
}

showStringProperties(Technology);
console.log('----------');

Example 9 Sum of Multiples

Image 9 - Sum of Multiples

Syntax & Example: 9-sum-of-multiples.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>sum-of-multiples</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>9-sum-of-multiples!</h1>

  <h3>Write a function which Calculate the sum of multiples of 3 and 5 for a given limit</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('9-sum-of-multiples');

function sumOfMultiples(curLimit) {

  let sumOfMultipleValue = 0;

  for(let i = 0; i <= curLimit; i++) {
    if (i % 3 === 0 || i % 5 === 0) {
      // console.log(i);
      sumOfMultipleValue +=i;
    }
  }
  // return sumOfMultipleValue;
  console.log(`sumOfMultipleValue of 3 & 5 upto ${curLimit} digit is:`, sumOfMultipleValue);
}

sumOfMultiples(10);

Example 10 Netsted Loop Star Pattern

Image 10 - Netsted Loop Star Pattern

Syntax & Example: 10-netsted-loop-star-pattern.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>10-netsted-loop-star-pattern</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>10-netsted-loop-star-pattern!</h1>

  <h3>Write a function which Prints/Shows star-aestrikes (or any pattern) for the number of times and rows provided</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('10-netsted-loop-star-pattern');

function showPattern(totalRowsPatternCount) {
  for (let curRow = 1; curRow <= totalRowsPatternCount; curRow++) {
    // console.log(curRow);
    let patternDesign = '';
    for (let i = 0; i < curRow; i++) {
      patternDesign += '*'
    }
    console.log(patternDesign);
  }
}

showPattern(5);

Example 11 Marks Average Grade

Image 11 - Marks Average Grade

Syntax & Example: 11-marks-average-grade.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>marks-average-grade</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>11-marks-average-grade!</h1>

  <h3>Write a function which Calculate the sum of marks provided in an array, average it and also show Grade</h3>

  Grade criteria/mechanism is:
  <ul>
    <li>0% to 70% => D Grade</li>
    <li>71% to 79% => C Grade</li>
    <li>81% to 89% => B Grade</li>
    <li>91% to 100% => A Grade</li>
  </ul>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('11-marks-average-grade');

// approach 1

/* const MARKSARRAY = [55, 85, 55, 65];

function calculateAverageGrade(currentMarks) {
  let totalMarks = 0;
  let averageMarks = 0;
  let grade;

  for(let mark of currentMarks) {
    totalMarks += mark;
  }
  // console.log('totalMarks:', totalMarks);
  averageMarks = (totalMarks/currentMarks.length);
  // console.log('averageMarks:', averageMarks);

  if(averageMarks < 70) return grade = 'D'; 
  if(averageMarks < 80) return grade = 'C';
  if(averageMarks < 90) return grade = 'B';
  if(averageMarks <= 100) return grade = 'A';
}

console.log('Grade:', calculateAverageGrade(MARKSARRAY)); */

// approach 2 - create two different functions with single responsibility principle

const MARKSARRAY = [55, 85, 55, 65];

function calculateAverage(currentArray) {
  let total = 0;
  for (let curValue of currentArray) {
    total += curValue;
  }
  // console.log('total:', total);
  return (total/currentArray.length);
}

// console.log(calculateAverage(MARKSARRAY));

function calculateGrades(_currentArray) { 
  const average = calculateAverage(_currentArray);
  // console.log('average:', average);

  if(average < 70) return grade = 'D'; 
  if(average < 80) return grade = 'C';
  if(average < 90) return grade = 'B';
  if(average <= 100) return grade = 'A';
}

console.log('Grade:',calculateGrades(MARKSARRAY));

Example 12 Random Bingo Card

Image 12 - Random Bingo Card

Syntax & Example: 12-random-bingo-card.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>random-bingo-card</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>12-random-bingo-card!</h1>
  
  <h3>Write a function to create a Bingo Card with Random numbers upto 75</h3>
  <table>
    <thead>
      <tr>
        <th class="heading">B</th>
        <th class="heading">I</th>
        <th class="heading">N</th>
        <th class="heading">G</th>
        <th class="heading">O</th>
      </tr>
    </thead>

    <tbody>
      <tr> 
        <td id="Square1">&nbsp;</td>
        <td id="Square2">&nbsp;</td>
        <td id="Square3">&nbsp;</td>
        <td id="Square4">&nbsp;</td>
        <td id="Square5">&nbsp;</td>
      </tr>
      <tr>
        <td id="Square6">&nbsp;</td>
        <td id="Square7">&nbsp;</td>
        <td id="Square8">&nbsp;</td>
        <td id="Square9">&nbsp;</td>
        <td id="Square10">&nbsp;</td>
      </tr>
      <tr>
        <td id="Square11">&nbsp;</td>
        <td id="Square12">&nbsp;</td>
        <td id="freeSquare">Free</td>
        <td id="Square13">&nbsp;</td>
        <td id="Square14">&nbsp;</td>
      </tr>
      <tr>
        <td id="Square15">&nbsp;</td>
        <td id="Square16">&nbsp;</td>
        <td id="Square17">&nbsp;</td>
        <td id="Square18">&nbsp;</td>
        <td id="Square19">&nbsp;</td>
      </tr>
      <tr>
        <td id="Square20">&nbsp;</td>
        <td id="Square21">&nbsp;</td>
        <td id="Square22">&nbsp;</td>
        <td id="Square23">&nbsp;</td>
        <td id="Square24">&nbsp;</td>
      </tr>
    </tbody>
  </table>

  <h3><a href="">Click here</a> (Reload/Refresh) to create Random Bingo Card!</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('12-random-bingo-card');

window.onload = createBingoCard;

function createBingoCard() {
  // console.log('in createBingoCard');

  for (var i = 1; i <= 24; i++) {
    var newRandomNum = Math.floor(Math.random() * 75);
    // console.log('newRandomNum', newRandomNum);
    document.getElementById('Square' + i).innerHTML = newRandomNum;
  }
}

Example 13 Show Prime Numbers

Image 13 - Show Prime Numbers

Syntax & Example: 13-show-prime-numbers.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>show-prime-numbers</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>13-show-prime-numbers!</h1>

  <h3>Write a function which show or print Prime Number upto provided range</h3>

  <ul>
    <li>Prime Numbers are those numbers whose factors are only `1` and `the number itself`</li>
    <li>In simple language Prime Numbers are divisible by only `1` and `the number itself/himself`</li>
    <li>Prime Numbers have only two factors: `1` and `the number itself/himself`</li>
    <li>Example: 2, 3, 5, 7, 11, 13, 17, 19 and so on...</li>
  </ul>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('13-show-prime-numbers');

// approach 1

/* function showPrimeNumbers(numberLimit) {
  for (let curNum = 2; curNum <= numberLimit; curNum++) {
    // console.log('curNum', curNum);

    let isPrime = true;
    for (let factor = 2; factor < curNum; factor++) {
      // console.log('factor', factor);
      if (curNum % factor === 0) {
        isPrime = false;
        break;
      }
    }

    if (isPrime) {
      console.log('Prime Number', curNum);
      
    }
  }
} 

showPrimeNumbers(20);*/

// approach 2

function showPrimeNumbers(numberLimit) {
  for (let curNum = 2; curNum <= numberLimit; curNum++) {
    // console.log('curNum', curNum);
    if (isPrimeNumber(curNum)) {
      console.log('Prime Number:', curNum);
    }
  }
}

function isPrimeNumber(_number) {
  for (let factor = 2; factor < _number; factor++) {
    // console.log('factor', factor);
    if (_number % factor === 0) {
      return false;
    }
  }
  return true;
}

showPrimeNumbers(20);

Example 14 Sum Of Arguments

Image 14 - Sum Of Arguments

Syntax & Example: 14-sum-of-arguments.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>sum-of-arguments</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>14-sum-of-arguments!</h1>

  <h3>Write a function which show or print Sum of Arguments passed</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('14-sum-of-arguments');

function sumOfArguments(...items){
  // rest operator converts anything passed as an array
  console.log('current items/values to add:', items);
  return items.reduce((n1, n2) => n1 +n2);
}

console.log('Sum:', sumOfArguments(10, 2, 8, 4, 6));
// console.log('Sum:', sumOfArguments([10, 2, 8, 4, 6]));

Example 15 Sum Of Arguments Array

Image 15 - Sum Of Arguments Array

Syntax & Example: 15-sum-of-arguments-array.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>sum-of-arguments-array</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>15-sum-of-arguments-array!</h1>

  <h3>Write a function which show or print Sum of Arguments passed as an Array</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('15-sum-of-arguments-array');

function sumOfArguments(...items){
  // as rest operator converts anything passed as an array check following
  if(items.length === 1 && Array.isArray(items[0])) {
    // reset item as a new array 
    items = [...items[0]]
    console.log('current items/values to add:', items);
    return items.reduce((n1, n2) => n1 +n2);
  }
}

// pass arguments as an array
// console.log('Sum:', sumOfArguments([10, 2, 8, 4, 6]));
console.log('Sum:', sumOfArguments([10, 2, 8, 4, 6]));

Example 16 Circle Area Object Read Only Property

Image 16 - Circle Area Object Read Only Property

Syntax & Example: 16-circle-area-object-read-only-property.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>circle-area-object-read-only-property</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>16-circle-area-object-read-only-property!</h1>

  <h3>Create an object with read only propety named 'area'</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('16-circle-area-object-read-only-property');

const CIRCLE = {
  name: 'mainCircle',
  lineColor: 'red',
  bgColor: 'gray',
  radius: 1,
  get area() {
    return Math.PI * this.radius * this.radius;
  }
}

console.log('CIRCLE.area:', CIRCLE.area);

Example 17 Create Array From Argument Range

Image 17 - Create Array From Argument Range

Syntax & Example: 17-create-array-from-argument-range.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>create-array-from-argument-range</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>17-create-array-from-argument-range!</h1>

  <h3>Create an array of the values from the 'min' and 'max' (start & end) range provided</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('17-create-array-from-argument-range');

function generateArrayFromRange(startNum, endNum) {
  const rangeArray = [];
  for(let curNum = startNum; curNum <= endNum; curNum++) {
    // console.log('curNum: ', curNum);
    rangeArray.push(curNum);
    // console.log('rangeArray: ', rangeArray);
  }
  return rangeArray;
}

const range1 = generateArrayFromRange(1, 5);
console.log(range1);
console.log('----------');
const range2 = generateArrayFromRange(-5, 0);
console.log(range2);

Example 18 Array Includes Element Exists

Image 18 - Array Includes Element Exists

Syntax & Example: 18-array-includes-element-exists.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>array-includes-element-exists</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>18-array-includes-element-exists!</h1>

  <h3>Create a method named 'includes' which checks an element exists in an array</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('18-array-includes-element-exists');

function includes(arrayToSearch, elementToSearch) {
  console.log('arrayToSearch: ', arrayToSearch);
  console.log('elementToSearch: ', elementToSearch);
  for(let curElement of arrayToSearch) {
    if(curElement === elementToSearch) {
      return true;
    } 
  }
  return false;
}

const versionArray = [1, 2, 5, 7, 2];
console.log(includes(versionArray, 2));
console.log('---------');
const ageArray = [21, 22, 25, 27, 25];
console.log(includes(ageArray, 30));

Example 19 Array Excludes Value To New Array

Image 19 - Array Excludes Value To New Array

Syntax & Example: 19-array-excludes-value-to-new-array.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>array-excludes-value-to-new-array</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>19-array-excludes-value-to-new-array!</h1>

  <h3>Create a method named 'excludes' which cut/excludes values from existing array and push to new array</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('19-array-excludes-value-to-new-array');

function excludes(arrayToExclude, elementsToExcluded) {
  console.log('arrayToExclude: ', arrayToExclude);
  console.log('elementsToExcluded: ', elementsToExcluded);
  const outputArray = [];
  for(let curElement of arrayToExclude) {
    if(!elementsToExcluded.includes(curElement)) {
      outputArray.push(curElement)
    }
  }
  return outputArray;
}

const versionArray = [1, 2, 5, 7, 2];
const newVesionArray = (excludes(versionArray, [2]));
console.log('newVesionArray: ', newVesionArray);

console.log('---------');

const ageArray = [21, 25, 22, 25, 30, 25, 30];
const newAgeArray = (excludes(ageArray, [25,30]));
console.log('newAgeArray: ', newAgeArray);

Example 20 Array Count Search Occurances

Image 20-01 - Array Count Search Occurances

Syntax & Example: array-count-search-occurances.html

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>array-count-search-occurances</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>
<body> 
  
  <h1>20-array-count-search-occurances!</h1>

  <h3>Create a function which counts the search occurances from an array</h3>

  <script type="text/javascript" src="script.js"></script>

</body>
</html>

Syntax & Example: script.js

console.log('20-array-count-search-occurances');

// approach 1
/* function countSearchOccurances(arrayToSearch, elementsToSearch) {
  // console.log('arrayToSearch: ', arrayToSearch);
  // console.log('elementsToSearch: ', elementsToSearch);
  let count = 0;
  for(let curElement of arrayToSearch) {
    if(curElement === elementsToSearch) {
      count++;
    }
  }
  // console.log('search count:', count);
  return count;
} */

// approach 2 
function countSearchOccurances(arrayToSearch, elementsToSearch) {

  return arrayToSearch.reduce((countAccumulator, curentSearchElement) => {
    let countOccurances = (curentSearchElement === elementsToSearch) ? 1 : 0;
    // console.log('countAccumulator', countAccumulator, 'arrayToSearch', arrayToSearch, 'elementsToSearch', elementsToSearch,);
    return countAccumulator + countOccurances;
  },0)
}

const versionArray = [1, 2, 5, 7, 2];
const versionCount = (countSearchOccurances(versionArray, 2));
console.log('versionCount: ', versionCount);

console.log('---------');

const ageArray = [21, 25, 22, 25, 30, 25, 30];
const ageCount = (countSearchOccurances(ageArray, -25));
console.log('ageCount: ', ageCount);

Image 20-02 - Array Count Search Occurances

Example 21 - Array Get Max Largest Number

Image 21 - Array Get Max Largest Number

Syntax & Example: 21-array-get-max-largest-number.html

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>array-get-max-largest-number</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>

<body>

  <h1>21-array-get-max-largest-number!</h1>

  <h3>Create a function which returns the maximum ie. largest number from an array</h3>

  <script type="text/javascript" src="script.js"></script>

</body>

</html>

Syntax & Example: script.js

console.log('21-array-get-max-largest-number');

// approach 1
/* 
function getLargestNumber(arrayToSearch) {
  if (arrayToSearch.length <= 0) return 'Array is Empty! Nothing to search!!';
  let largetNumber = arrayToSearch[0];

  for (let i = 1; i < arrayToSearch.length; i++) {
    if (arrayToSearch[i] > largetNumber) {
      largetNumber = arrayToSearch[i];
    }
  }
  return largetNumber;
} 

const versionArray = [5, 2, 3, 4, 7];
const largestVersion = (getLargestNumber(versionArray));
console.log('largestVersion: ', largestVersion);

console.log('---------');

const ageArray = [21, 25, 22, 25, 30, 25, 30];
const maxAge = (getLargestNumber(ageArray));
console.log('maxAge: ', maxAge); */

// approach 2 

function getLargestNumber(arrayToSearch) {
  if (arrayToSearch.length <= 0) return 'Array is Empty! Nothing to search!!';

  return arrayToSearch.reduce((largetNumber, curentSearchElement) => {
    return (curentSearchElement > largetNumber) ? curentSearchElement : largetNumber;
  })
}

const versionArray = [5, 2, 3, 4, 7];
const largestVersion = (getLargestNumber(versionArray));
console.log('largestVersion: ', largestVersion);

console.log('---------');

const ageArray = [21, 25, 22, 25, 30, 25, 30];
const maxAge = (getLargestNumber(ageArray));
console.log('maxAge: ', maxAge);

Example 22 Array Filter Sort Map

Image 22 - Array Filter Sort Map

Syntax & Example: 22-array-filter-sort-map.html

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>array-filter-sort-map</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>

<body>

  <h1>22-array-filter-sort-map!</h1>

  <h3>Array: Filter the array of students with Higest Ranking, Sort on Ranking, finally Show the Names </h3>

  <script type="text/javascript" src="script.js"></script>

</body>

</html>

Syntax & Example: script.js

console.log('22-array-filter-sort-map');

const studentsArray = [
  { name: 'Suraj', year: 2019, ranking: 4 },
  { name: 'Amit', year: 2019, ranking: 5 },
  { name: 'Akash', year: 2018, ranking: 4 },
  { name: 'Dinanath', year: 2019, ranking: 7 },
  { name: 'Sagar', year: 2017, ranking: 3 },
]

console.log('Higest Rank Holders:',
  studentsArray
    .filter(student => student.year === 2019 && student.ranking >= 5)
    .sort((n1, n2) => n1.ranking - n2.ranking)
    .reverse()
    .map(student => student.name)
);

Example 23 Object Create Students and Address Object

Image 23 - Object Create Students and Address Object

Syntax & Example: 23-object-create-students-and-address-object.html

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>object-create-students-and-address-object</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>

<body>

  <h1>23-object-create-students-and-address-object!</h1>

  <h3>Create an Object for Students and Address with various Properties and Methods </h3>

  <script type="text/javascript" src="script.js"></script>

</body>

</html>

Syntax & Example: script.js

console.log('23-object-create-students-and-address-object');

const Students = {
  name: 'Dinanath',
  age: 35,
  rank: 5,
  country: 'India',
}

const Address = {
  street: 'Sir DJ Road',
  city: 'Mumbai',
  pinCode: 401209,
  state: 'MH',
  country: 'India',
}

function showObjectDetails(obj) {
  for(let key in obj) {
    console.log(key,' : ',obj[key]);
  }
}

showObjectDetails(Students);
console.log('----------');
showObjectDetails(Address);

Example 24 Object Create Object Factory Constructor Function

Image 24 - Object Create Object Factory Constructor Function

Syntax & Example: 24-object-create-object-factory-constructor-function.html

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>object-create-object-factory-constructor-function</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>

<body>

  <h1>24-object-create-object-factory-constructor-function!</h1>

  <h3>Create an Object of Students by using Factory and Constructor methods</h3>

  <script type="text/javascript" src="script.js"></script>

</body>

</html>

Syntax & Example: script.js

console.log('24-object-create-object-factory-constructor-function');

// Factory function/method - camelCasing - camel notation - use return keyword
function createObjFactoryMethod(name, age, rank, country) {
  return {
    name, age, rank, country
  }
}

let Students1 = createObjFactoryMethod('Dinanath', 35, 5, 'India');
console.log('Students1', Students1);

// Constructor function/method - pascalCasing - pascal notation - use this keyword
function Student(name, age, rank, country) {
  this.name = name;
  this.age = age;
  this.rank = rank;
  this.country = country;
}

let Students2 = new Student('Amit', 30, 4, 'Hindustan');
console.log('Students2', Students2);

Example 25 Object Equality

Image 25 - Object Equality

Syntax & Example: 25-object-equality.html

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>object-equality</title>
  <link rel="stylesheet" type="text/css" href="../style.css" />
</head>

<body>

  <h1>25-object-equality!</h1>

  <h3>Write function to check object equality</h3>

  <script type="text/javascript" src="script.js"></script>

</body>

</html>

Syntax & Example: script.js

console.log('25-object-equality');

// Constructor function/method - pascalCasing - pascal notation - use this keyword
function Student(name, age, rank, country) {
  this.name = name;
  this.age = age;
  this.rank = rank;
  this.country = country;
}

let Students1 = new Student('Dinanath', 35, 5, 'India');
console.log('Students1', Students1);

let Students2 = new Student('Dinanath', 35, 5, 'India');
console.log('Students2', Students2);

console.log('----------');

// Objects are reference type, objects can have same properties but they are from different memeory location, they can be equal if both objects have same properties
function isObjectEqual(obj1, obj2){
  return obj1.name === obj2.name &&
         obj1.age === obj2.age &&
         obj1.rank === obj2.rank &&
         obj1.country === obj2.country
}

console.log('isEqual', isObjectEqual(Students1, Students2));

console.log('----------');

// Objects are same if both are pointed to same object
function isObjectPointSame(obj1, obj2){
  return obj1 === obj2;
}

let isSame1 = isObjectPointSame(Students1, Students2);
console.log('isSame1', isSame1);

let Students3 = Students2;
let isSame2 = isObjectPointSame(Students2, Students3);
console.log('isSame2', isSame2);

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JavaScript Essential exercise for Beginners

JavaScript exercise/examples for Beginners

01. What is JavaScript?

02. What can JavaScript do?

03. What can't JavaScript do?

Topics include

Example 1 swapping variables

Example 2 max number

Example 3 Landscape Portrait

Example 4 FizzBuzz Algorithms

Example 5 Speed Limits

Example 6 Odd Even Number Loop

Example 7 Count Truthy Falsy Values

Example 8 Object String Properties Key

Example 9 Sum of Multiples

Example 10 Netsted Loop Star Pattern

Example 11 Marks Average Grade

Example 12 Random Bingo Card

Example 13 Show Prime Numbers

Example 14 Sum Of Arguments

Example 15 Sum Of Arguments Array

Example 16 Circle Area Object Read Only Property

Example 17 Create Array From Argument Range

Example 18 Array Includes Element Exists

Example 19 Array Excludes Value To New Array

Example 20 Array Count Search Occurances

Example 21 - Array Get Max Largest Number

Example 22 Array Filter Sort Map

Example 23 Object Create Students and Address Object

Example 24 Object Create Object Factory Constructor Function

Example 25 Object Equality

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