What are some examples of custom validators in programming?

What are some examples of custom validators in programming?

Custom validators are functions that check if data meets specific criteria. For example, in a form, you might want to ensure a password is at least 8 characters long and contains a number.

Can you give me a specific code example?

Sure! In JavaScript, you could create a custom validator like this:

function validatePassword(password) {
    const hasNumber = /\\d/;
    return password.length >= 8 && hasNumber.test(password);
}

This function checks if the password is at least 8 characters long and contains a number.

What about in Python?

In Python, you could write a custom validator like this:

def validate_email(email):
    return '@' in email and '.' in email

This function checks if the email contains both '@' and '.'.

Are there any libraries that help with custom validation?

Yes, libraries like Joi for JavaScript and Marshmallow for Python provide built-in validators and allow you to create custom ones easily.