What does pre mean in php

The pre function in PHP is used to output the contents of the variable as is, without escaping special characters, thus retaining the original format and value of the variable, which is very useful when debugging and viewing the contents of the variable.

pre in PHP

Short answer:

pre It is a built-in function in PHP, which is used to output the contents of variables as they are without escaping special characters.

Detailed description:

Function:

The main function of the pre function is to output the contents of the variable while retaining its original formats and special characters. This is useful for debugging and viewing variable contents, as it shows the exact structure and value of the variable.

Usage:

pre The syntax of the function is as follows:

pre(mixed $value)

Among them, $value is the variable to be output.

Special character processing:

Unlike other output functions in PHP (such as echo and print), the pre function does not process special characters (such as HTML entities and conversion meaning sequence) to escape. This allows it to output the contents of the variable unchanged, including formatting and special characters.

Example:

The following example demonstrates how to use the pre function to output the contents of an array:

<?php
$array = array('name' => 'John Doe', 'age' => 30);
pre($array);

The output result is:

<code>Array
(
    [name] => John Doe
    [age] => 30
)</code>

As you can see, the contents of the array are output as is, including special characters (such as single quotes).

Note:

It should be noted that the pre function does not escape HTML special characters, so you need to be extra careful when outputting HTML content. If you need to escape HTML special characters, you can use the htmlspecialchars() function.

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