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 create a validator to ensure a password is strong enough.

Can you give me a specific example of a custom validator?

Sure! In JavaScript, you could create a custom validator to check if an email address is in a valid format using a regular expression.

How would I implement that in a form?

You would attach the custom validator to the form's submit event, checking the email input against your regex pattern before allowing submission.

Are there any libraries that can help with custom validation?

Yes, libraries like Joi and Yup in JavaScript provide built-in methods for creating custom validators easily.