The role of die function in php

The die function in PHP is to immediately terminate script execution and output a message string. This function is used when a serious error or exception is detected, script execution needs to be stopped immediately, or error information is sent to a log file. Alternatives include the exit() function and throw exceptions.

The role of the die function in PHP

The die function is used in PHP to immediately terminate script execution and output a Optional message string.

Usage:

die([message]);

where [message] is an optional message string.

Function:

The die function immediately terminates script execution at the point where it is called and outputs the following:

• If is provided [message] parameter, the string will be output.
• If the [message] parameter is not provided, a default message (i.e. "Fatal error: Call to undefined function die()") is output.

When to use:

The die function is typically used in the following situations:

• When a serious error or exception is detected, to provide immediate feedback to users.
• Needs to stop script execution immediately, for example in case of validation failure or data processing error.
• Send specific error information to the log file.

Example:

The following code example demonstrates the use of the die function:

<?php
if ($user_id <= 0) {
  die("无效的用户 ID");
}

// 继续执行脚本...

Alternative approach:

In some cases, other alternatives can be used to terminate script execution, such as:

• Using the exit() function: exit([ message])
• Use throw to throw an exception: throw new Exception([message])

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