How to validate phone number using regex in TypeScript or JavaScript?

 In order to validate phone numbers using regular expression (regex), you need to define a pattern that matches the format of the phone numbers you want to accept. Here is an example of a regex pattern that validates phone numbers in the format of "(XXX) XXX-XXXX" (where X represents a digit):

typescript
const phoneRegex = /^\(\d{3}\) \d{3}-\d{4}$/;

function validatePhone(phoneNumber: string): boolean {
  return phoneRegex.test(phoneNumber);
}

// Example usage
console.log(validatePhone("(123) 456-7890")); // Output: true
console.log(validatePhone("123-456-7890")); // Output: false

In the example above, the regular expression phoneRegex matches any string that contains:

• An opening parenthesis (.
• Three digits \d{3}.
• A closing parenthesis ).
• A space character.
• Three digits \d{3}.
• A hyphen -.
• Four digits \d{4}.

The validatePhone function takes a phone number as input and returns true if the phone number matches the regular expression, and false otherwise.

Note that this regular expression is just an example and may not match all possible valid phone numbers. You may need to adjust the pattern to match the specific format of phone numbers you want to accept.