Course

Introduction

Print Hello World Add Two Numbers Find the Square Root Calculate the Area of a Triangle Swap Two Variables Convert Kilometers to Miles Convert Celsius to Fahrenheit Work With Constants Write to Console

Control Flow

Solve Quadratic Equation Check if a number is Positive, Negative, or Zero Check if a Number is Odd or Even Find the Largest Among Three Numbers Check Prime Number Print All Prime Numbers in an Interval Find the Factorial of a Number Display the Multiplication Table Print the Fibonacci Sequence Check Armstrong Number Find Armstrong Number in an Interval Make a Simple Calculator Find the Sum of Natural Numbers Check if the Numbers Have Same Last Digit Find HCF or GCD Find LCM Find the Factors of a Number Display Fibonacci Sequence Using Recursion

Functions

Generate a Random Number Find Sum of Natural Numbers Using Recursion Guess a Random Number Find Factorial of Number Using Recursion Convert Decimal to Binary Find ASCII Value of Character Set a Default Parameter Value For a Function Check If a Variable is of Function Type Pass Parameter to a setTimeout() Function Perform Function Overloading Pass a Function as Parameter

Arrays and Objects

Shuffle Deck of Cards Create Objects in Different Ways Remove a Property from an Object Check if a Key Exists in an Object Clone a JS Object Loop Through an Object Merge Property of Two Objects Count the Number of Keys/Properties in an Object Add Key/Value Pair to an Object Convert Objects to Strings Replace all Instances of a Character in a String Remove Specific Item From an Array Check if An Array Contains a Specified Value Insert Item in an Array Append an Object to an Array Check if An Object is An Array Empty an Array Add Element to Start of an Array Remove Duplicates From Array Merge Two Arrays and Remove Duplicate Items Sort Array of Objects by Property Values Create Two Dimensional Array Extract Given Property Values from Objects as Array Compare Elements of Two Arrays Get Random Item From an Array Perform Intersection Between Two Arrays Split Array into Smaller Chunks Check If A Variable Is undefined or null Illustrate Different Set Operations

Miscellaneous

Display Date and Time Check Leap Year Format the Date Display Current Date Compare The Value of Two Dates Create Countdown Timer Include a JS file in Another JS file Generate a Random Number Between Two Numbers Get The Current URL Validate An Email Address Implement a Stack Implement a Queue Check if a Number is Float or Integer Get the Dimensions of an Image Convert Date to Number

JavaScript Program to Validate An Email Address

To understand this example, you should have the knowledge of the following JavaScript programming topics:

Example: Using Regex


              
// program to validate an email address

function validateEmail(email_id) {
    const regex_pattern =      /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;

    if (regex_pattern.test(email_id)) {
        console.log('The email address is valid');
    }
    else {
        console.log('The email address is not valid');
    }
}

validateEmail('[email protected]');
validateEmail('hello@com');

Output


              
The email address is valid
The email address is not valid

In the above program, the regular expression pattern


              
/^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/

checks if an email address is valid or not.

The test() method returns true if there is a match in the string with the regex pattern.

The regular expression (regex) describes a sequence of characters used for defining a search pattern.