JavaScript: Check whether the pattern of an e-mail address matches a specific format

JavaScript validation with regular expression: Exercise-3 with Solution

Email Pattern

Write a pattern that matches e-mail addresses.

The personal information part contains the following ASCII characters.

Sample Solution: 1

JavaScript Code:

function valid_email(str)
{
var mailformat = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/;  
if(mailformat.test(str))
{  
console.log("Valid email address!");  
}  
else  
{  
console.log("You have entered an invalid email address!");  
}
}

valid_email('[email protected]');

Output:

Valid email address!

Flowchart:

Sample Solution:- 2

JavaScript Code:

function is_email(str)
{
 // Scott Gonzalez: Email address validation
  
  regexp = /^((([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+(\.([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+)*)|((\x22)((((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(([\x01-\x08\x0b\x0c\x0e-\x1f\x7f]|\x21|[\x23-\x5b]|[\x5d-\x7e]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(\\([\x01-\x09\x0b\x0c\x0d-\x7f]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))))*(((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(\x22)))@((([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.)+(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))$/i;
  
        if (regexp.test(str))
        {
          return true;
        }
        else
        {
          return false;
        }
}

console.log(is_email("[email protected]"));
console.log(is_email("[email protected] "));

Live Demo:

See the Pen javascript-regexp-exercise-3 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript regular expression that matches a valid e-mail address following the given ASCII character rules.
• Write a JavaScript function that uses a regex pattern to extract the username and domain parts of an e-mail address.
• Write a JavaScript function that tests multiple e-mail addresses against your regex and returns those that match the criteria.
• Write a JavaScript function that refines a regex to disallow consecutive dots and ensure the personal part does not start or end with a dot.

Improve this sample solution and post your code through Disqus.

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