Validate Input

Let's try validating input from a form.

The first thing we need to do is to confirm that the input data we are looking for exists.

Then we filter the input data using the filter_input() function.

In the example below, the input variable "email" is sent to the PHP page:

< ?php if(!filter_has_var(INPUT_GET, "email")) { echo("Input type does not exist"); } else { if (!filter_input(INPUT_GET, "email", FILTER_VALIDATE_EMAIL)) { echo "E-Mail is not valid"; } else { echo "E-Mail is valid"; } } ? >

Example Explained

The example above has an input (email) sent to it using the "GET" method:

1. Check if an "email" input variable of the "GET" type exist

2. If the input variable exists, check if it is a valid e-mail address