1. Program to print Hello World
<html>
<head>
<script language=”JavaScript”>
document.write(“<font color=’red’ size=’4′>Hello world</font>”)
</script>
</head>
</html>
Output:
2. Addition of two numbers
<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>
Output:
Sum: 50
3. Program to Add, subtract, multiply, and divide
<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>
Output:
Add = 110
Subtract = 90
Multiply = 1000
Divide = 10
4. Program to input value from the user using prompt
<html>
<head>
<script>
var name=prompt(“Enter your name: “);
document.write(“Welcome “+ name);
</script>
<style>
body {
color: #FFFF00;
background: #EE82EE;
font-size: 30px;
}
</style>
</head>
<body>
</body>
</html>
Output:
5. Input an integer value and print it
<html>
<head>
<script>
var num = prompt(“Enter an integer value:”);
document.write(“Entered Number is “, num);
</script>
</head>
</html>
Output:
6. Add two numbers taking input from user
<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 two numbers : ” + sum)
</script>
</head>
</html>
Output:
7. Program to add two float values
<html>
<head>
<script>
var num1 = 4.12;
var num2 = 9.87;
var result = 0;
// Adding float values
result =num1+ num2;
// Without rounding the result
document.write(“Without rounding: ” + result)
// Rounding the result to 2 digits after decimal
result = result.toFixed(2);
document.write(“<br>With rounding: ” + result)
</script>
</head>
</html>
Output:
Without rounding: 13.989999999999998
With rounding: 13.99
8. Program to swap values of two variables
<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(“The value of a and b before swapping: ” + a + ” ” + b)
//create a temporary variable
let temp;
//swap variables
temp = a;
a = b;
b = temp;
document.write(“<br>The value of a and b after swapping: ” + a + ” ” + b)
</script>
</head>
</html>
Output:
The value of a and b before swapping: 10 20
The value of a and b after swapping: 20 10
9. Program to check if the number is even or odd
<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>
Output:
12 is an Even Number
10. Program to check leap year
<html>
<head>
<script>
// program to check leap year
function checkLeapYear(year) {
if(year%4==0) {
document.write(year + ‘ is a leap year’);
}
else {
document.write(year + ‘ is not a leap year’);
}
}
// take input
const year=prompt(‘Enter a year:’);
checkLeapYear(year);
</script>
</head>
</html>
Output:
2020 is a leap year
11. Program to find the largest among three numbers
<html>
<head>
<script>
// take input from the user
const num1 = prompt(“Enter first number: “);
const num2 = prompt(“Enter second number: “);
const num3 = prompt(“Enter third number: “);
let 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>
Output:
The largest number is: 23
12. Program that checks if the number is positive, negative or zero
<html>
<head>
<script>
// input from the user
const 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>
Output:
The number is positive
The number is zero
The number is negative
13. Program to input age and check person is eligible for voting or not
<html>
<head>
<script>
function validate(age) {
if(age>=18) {
ans=”eligible”;
}
else {
ans=”not eigible”;
}
document.write(“You are <b>”+ ans +”</b> for Vote”);
}
var age=prompt(“Enter age”);
validate(age);
</script>
</html>
14. Program to Add n numbers
<html>
<body>
<script>
var i, n=5, sum=0;
arr = new Array(20, 22, 13, 15, 19);
for(i=0; i<n; i++)
sum = sum + arr[i];
document.write(“Sum of 5 numbers: ” + sum);
</script>
</body>
</html>
Output:
Sum of 5 numbers: 89
16. Program to Demonstrate Popup Boxes in JavaScript
<html>
<head>
<title>Popup Boxes in JavaScript</title>
<script>
alert(“Welcome to Our website!”);
confirm(“It is a Confirm popup box!”);
var name=prompt(“This is a prompt box!”, “Enter your name: “);
alert(“Welcome “+ name);
</script>
</head>
<body bgcolor=”seagreen”>
<div style=”text-align:center; color: #FFFF00; background: #EE82EE; font-size: 30px;”>
<h1>JavaScript Example to Demonstrate Popup Boxes!</h1>
</div>
</body>
</html>
Output:
