Custom validation rules are beneficial when built-in ones don’t meet specific requirements. For instance, consider a scenario where an application requires users to create passwords with unique criteria: at least one uppercase letter, one lowercase letter, one number, and one special character. Built-in validations may not cover this complexity.
In such cases, custom validation rules can be implemented. Using regular expressions (regex), we can define our own pattern that the password must match. Here’s a simple example in JavaScript:
function validatePassword(password) {
var regex = /^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$/;
return regex.test(password);
This function will return true if the password meets all the criteria, false otherwise. This is just one of many scenarios where custom validation rules would be more suitable than built-in ones due to their flexibility and adaptability to complex or unique situations.
