Include and Require functions
In PHP, include and require are used to include and evaluate files in your script. They allow you to modularize your code by breaking it into smaller, reusable pieces. While they serve similar purposes, there are key differences in how they handle errors and their impact on script execution.
include and require Functions
include
Purpose: The include statement is used to include and evaluate a specified file within the script. If the file is not found, PHP will emit a warning but continue executing the rest of the script.
Usage: Typically used for including files that are not critical to the execution of the script. For example, including a configuration file that provides default values.
Example:
php
include 'header.php'; // Includes header.php file
echo "This is the main content.";
If header.php is not found, PHP will issue a warning but will continue executing the script, so "This is the main content." will still be displayed.
require
Purpose: The require statement is used to include and evaluate a specified file. If the file is not found, PHP will emit a fatal error and stop the script execution.
Usage: Typically used for including files that are essential for the execution of the script. For example, including a file with function definitions that are necessary for the script to run.
Example:
php
require 'functions.php'; // Includes functions.php file
echo "This is the main content.";
If functions.php is not found, PHP will issue a fatal error and stop executing the script, so "This is the main content." will not be displayed.
Differences Between include and require
Error Handling:
include: Emits a warning if the file is not found but continues script execution.
require: Emits a fatal error if the file is not found and stops script execution.
Use Cases:
include: Used for files that are not crucial to the script’s functionality and can be safely omitted.
require: Used for files that are critical to the script’s functionality and must be included for the script to work properly.
