What does php description error mean?

php description error is a problem with the PHP program itself, usually caused by illegal syntax and environmental problems. The solution: 1. Create a PHP sample file; 2. Execute the PHP code as "$a= 0;echo 4/$a;"; 3. Use catch to capture exceptions or handle errors through the "set_error_handler" function.

Operating system for this tutorial: Windows 10 system, PHP version 8.1, Dell G3 computer.

What does php description error mean

PHP errors are problems of the PHP program itself. They are generally caused by illegal syntax and environmental problems, making the compiler unable to pass Check and even fail to run the situation. The warnings and notices you usually encounter are all errors, but they are at different levels.

PHP exception handling mechanism draws lessons from java c, etc., but PHP's exception handling mechanism is not sound. The purpose of the exception handling mechanism is to separate the code for normal execution of the program from the code for handling exceptions.

PHP cannot automatically catch exceptions (most of them), it can only actively throw exceptions and catch them. That is, exceptions are predictable.

Take the divisor as 0 as an example to see how PHP handles it

<?php 
$a = 0;
try {
	echo 4/$a;
}
catch (Exception $e){
	echo $e->getMessage();
}
//报错，PHP是无法自动捕获异常的，必须手动抛出
?>

Manually throw it below

<?php 
$a = 0;
try {
	if($a == 0){
		throw new Exception(&#39;除数不能为0&#39;, 1);
	}
	echo 4/$a;//不会执行
}
catch (Exception $e){
	echo $e->getMessage();
}
?>

You can see that catch capture Abnormality arrived.

The exception mechanism used in PHP is generally used for business logic judgment. When the business logic is abnormal, special processing is performed.

Let’s take a look at the PHP error handling mechanism. PHP provides the set_error_handler() function for error handling. When an error occurs, set_error_handler will handle the error uniformly.

As shown below

<?php 
$a = 0;
function handle($errno,$errstr,$errfile,$errline){
	echo $errfile;
}
set_error_handler(&#39;handle&#39;);

echo 4/$a;
echo PHP_EOL;
echo &#39;hehe&#39;;
?>

An error occurred in the above echo 4/$a;. At this time, it enters the error processing function handle for error processing. Generally, we Add die to the handle to terminate execution.

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