JavaScript – Exercises, Practice, Solution | JavaScript programming Examples

<!DOCTYPE html>

<html>

<head>

<script language=”JavaScript”>

document.write(“<font color=’red’ size=’7′ face=’monotype corsiva’> Welcome to JavaScript </font>”)

document.bgColor = “teal”

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<title>Adding two numbers </title>

<script>

var num1 = 10;

var num2 = 40;

var sum = num1 + num2;

document.write(“Sum = ” + sum);

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<script>

 var num1 = 100, num2 = 10, result;

 result = num1 + num2;

 document.write(“Add = ” + result + “<br>”);

 result = num1 – num2;

 document.write(“Subtract = ” + result + “<br>”);

 result = num1 * num2;

 document.write(“Multiply = ” + result + “<br>”);

 result = num1 / num2;

 document.write(“Divide = ” + result + “<br>”);

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<script>

var name = prompt(“Enter your name: “);

document.write(“Welcome “+ name);

</script>

<style>

body {

        color: #992288;

        background: #ffddff;

font-size: 20px;  }

</style>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<script>

var num = prompt(“Enter an integer value:”);

document.write(“Entered integer is : “,num);

</script>

</head> 

</html>

<!DOCTYPE html>

<html>

<head>

<title>Add two numbers</title>

<script language = “JavaScript”>

var num1 = parseInt(prompt(“Enter first number: “));

var num2 = parseInt(prompt(“Enter second number: “));

var sum = num1 + num2

alert(“Sum of “+num1+” and “+num2+” is: ” + sum)

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<script>

var num1 = 4.12, num2 = 9.87, result;

result = num1 + num2;

// Without rounding the result

document.write(“Result without rounding: ” + result)

// Rounding the result to 2 digits after decimal

result = result.toFixed(2);

document.write(“<br>Result with rounding: ” + result)

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<title>Swapping values of two variables</title>

<script>

//take input from the users

let a = prompt(‘Enter the value of a: ‘);

let b = prompt(‘Enter the value of b: ‘);

document.write(“Before swapping…”)

document.write(“a= “ + a + ” b= ” + b)

//create a temporary variable

let temp;

//swap variables

temp = a;

a = b;

b = temp;

document.write(“<br>After swapping…”)

document.write(“a= “ + a + ” b= ” + b)

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<script>

// take input from the user

var num = prompt(“Enter a number: “);

//check if the number is even

if(num%2 == 0)

document.write(num + ” is an Even Number”);

else

document.write(num + ” is an Odd Number”);

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<script>

// take input from the user

var year=prompt(‘Enter a year: ‘);

if(year%4==0)

document.write(year + ‘ is a leap year’);

else

document.write(year + ‘ is not a leap year’)

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<script>

// take input from the user

var num1 = prompt(“Enter first number: “);

var num2 = prompt(“Enter second number: “);

var num3 = prompt(“Enter third number: “);

var largest;

// check the condition

if(num1>num2&& num1>num3)

largest = num1;

else if (num2>num1&&num2>num3)

largest = num2;

else

largest = num3;

// display the result

document.write(“The largest number is: ” + largest);

</script>

</head>

<html>

<!DOCTYPE html>

<html>

<head>

<script>

// input from the user

var number = prompt(“Enter a number: “));

// check if number is greater than 0

if (number > 0)

document.write(“The number is positive”);

// check if number is 0

else if (number == 0)

document.write(“The number is zero”);

// if number is less than 0

else

document.write(“The number is negative”);

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<script>

var age = prompt(“Enter age: “);

if(age> = 18)

ans = “eligible”;

else

ans = “not eigible”;

document.write(“You are <b>”+ans+”</b> for Vote”);

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<script>

var day,dayName;

day = parseInt(prompt(“Enter number of weekdays: “));

switch(day) {

case 1:

dayName = “Monday”; break;

case 2:

dayName = “Tuesday”; break;

case 3:

dayName = “Wednesday”; break;

case 4:

dayName = “Thursday”; break;

case 5:

dayName = “Friday”; break;

case 6:

dayName = “Saturday”; break;

case 7:

dayName = “Sunday”; break;

default:

dayName = “Wrong Choice..”;

}

alert(“It is ” + dayName)

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<script>

document.write(“Numbers from 1 to 30 :<br><br>”)

for(let i = 1; i <= 30; i++) {

    document.write(i, ” “);

}

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<title> Popup Boxes in JavaScript </title>

<script>

alert(“This is an example of alert box!”);

confirm(“It is a Confirm popup box!”);

var name = prompt(“This is a prompt box!”, “Enter your name: “);

alert(“Welcome ” + name);

</script>

</head>

<body style = “background-color: seagreen”>

<h1 style = “text-align:center; color: #FFFF00; background: #EE82EE; font-size: 30px;”>JavaScript Example to Demonstrate Popup Boxes!</h1>

</body>

</html>

<!DOCTYPE html>

<html>

<head>

<script language = “JavaScript”>

RightNow = new Date();

document.write(“Today’s date is ” + (RightNow.getMonth()+1) + “-” + RightNow.getDate() + “-” + RightNow.getFullYear())

document.write(“<br>You entered this web page at exactly: ” + RightNow.getHours() + “:” + RightNow.getMinutes() + ” and ” + RightNow.getSeconds() + ” seconds”);

</script>

</head>

</html>

<!DOCTYPE html>

<html>

<head>

<script language = “javascript”>

function newcolor(color) {

alert(“You Choose ” + color)

document.bgColor = color

}

</script>

</head>

<body>

<h1>Select a background color</h1>

<form>

<input type = “button” value = “Pink” onClick = “newcolor(‘pink’)”>

<input type = “button” value = “Violet” onClick = “newcolor(‘violet’)”>

</form>

</body>

</html>

<!DOCTYPE html>

<html>

<head>

<SCRIPT LANGUAGE = “JavaScript”>

num = 0

img1 = new Image()

img1.src = “pic1.jpg”

img2 = new Image()

img2.src = “pic2.png”

img3 = new Image()

img3.src = “pic3.jpg”

img4 = new Image()

img4.src = “pic4.png”

img5 = new Image()

img5.src = “th.jpg”

img6 = new Image()

img6.src = “img.jpg”

function startanimation() {

num = num+1

if(num > 6)

num = 1

document.mypic.src = eval(“img”+num+”.src”)

setTimeout(“startanimation()”,500)

document.bgColor = “teal”

}

</script>

</head>

<body>

<center>

<img src = “pic1.jpg” name = “mypic” border = “0”>

<script language = “javascript”>

startanimation()   //calling script from another script

</script>

</center>

</body>

</html>