php die exit difference

The difference between exit() and die() in PHP

PHP Manual: die()Equivalent to exit ().

Explanation: die() and exit() are both functions to terminate script execution; in fact, the two names exit and die point to the same function, die() is exit() Alias ​​for the function. This function only accepts one parameter, which can be a value returned by a program or a string, or no parameters can be entered, and the result is no return value.

Reference: Although the two are the same, there are subtle selectivity in common use.

For example: When the value passed to the exit and die functions is 0, it means that the execution of the script is terminated early, usually using the name exit().

echo "1111";
exit(0);
echo "2222";  // 22222不会被输出，因为程序运行到exit(0)时，脚本已经被提前终止，“马上断气”。

When the program errors, you can pass it a string, which will be output as it is on the system terminal, usually using the name die().

$fp=fopen("./readme.txt","r") or die("不能打开该文件");
// 这种情况下，如果fopen函数被调用返回布尔值false时，die()将立即终止脚本，并马上打印
// 传递给它的字符串，“死前还能说一两句话”。

1. Functionally, die() is equivalent to exit();

2. PHP has multiple running methods, namely website form , also available in script form (no web server required).

When PHP is running in script form, it is recommended to use exit():

For example, when the Bash Shell script language wants to stop running, it will Use the exit() function to terminate the script and allow the output point content to the running environment (usually stored in a global variable), but the output content can only be a number, indicating the "end status of the command".

In other words, exit(123) only outputs a running status 123, rather than actually outputting the string 123 to the console. If you want to output 123 to the console, the code must be changed to the following form:

<?php
exit(&#39;123&#39;);?>

When PHP is running as a website, it is recommended to use die():

But this When die (number), it is meaningless, because it will not output a number string to the page. In other words, if you want the page to terminate and output numbers, you have to change it to the following form

<?php
die(&#39;123&#39;);?>

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