JavaScript validation method

In web development, validating user-entered data is a very important task. JavaScript provides a variety of verification methods that can be used to verify user-entered form data, user identity, etc. This article will introduce some commonly used JavaScript verification methods and provide corresponding source code examples.

1. non-null check

The non-null check is one of the most basic checks, used to ensure that the value entered by the user is not empty. The following is a simple non-null check function:

function validateNotEmpty(value) {
   
    
    
  if (value.trim() === '') {