html phone number input validation code example

Example 1: html textbox pattern mobile number

<input type="text" name="Phone Number" pattern="[7-9]{1}[0-9]{9}" 
       title="Phone number with 7-9 and remaing 9 digit with 0-9">

Example 2: phone number validation html

How about this? /(7|8|9)\d{9}/

It starts by either looking for 7 or 8 or 9, and then followed by 9 digits.