Various types of password validation in JavaScript

Password Validation

Password validation is the authentication process during the form filling at any website.

It includes various formats, according to which a user must create the password. The different kinds of formats are described below in this blog.

To check a password between 6 to 20 characters which contains at least one numeric digit, one uppercase, and one lowercase letter,

JavaScript code

<script>  
   function CheckPassword(inputtxt) {  
      var passw = /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).{6,20}$/;  
      if (inputtxt.value.match(passw)) {  
         alert('Correct, try another...')  
         return true;  
      }  
      else {  
         alert('Wrong...!')  
         return false;  
      }  
   }  
</script> 

To check a password between 7 to 16 characters, which should contain only characters, numeric digits, and underscore, and the first character must be a letter,

JavaScript code

var passw= /^[A-Za-z]\w{7,14}$/; 

To check a password between 7 to 15 characters, which should contain at least one numeric digit and a special character,

JavaScript code

var passw= /^(?=.*[0-9])(?=.*[!@#$%^&*])[a-zA-Z0-9!@#$%^&*]{7,15}$/; 

To check a password between 8 to 15 characters, which should contain at least one lowercase letter, one uppercase letter, one numeric digit, and one special character,

Javascript code

var passw= /^(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[^a-zA-Z0-9])(?!.*\s).{8,15}$/; 

The other type can also be made by applying different logic.