First, let's look at two special characters: '^' and '$' which are used to match the beginning and end of a string, respectively, to illustrate: quot; ^Thequot; a string that matches quot; Thequot; the beginning of a str...
When we use PHP to develop web sites, we often use forms validation, such as whether the email format is legal, only allow input numbers, and so on. Here are some forms validation functions commonly used on the server si...