Exception handling is used to handle errors in PHP functions, which is implemented through try-catch statement blocks. If the code in the try block throws an exception, execution flows to the exception handler in the catch block. PHP provides exception classes such as Exception and ArithmeticError to represent specific error types.
Exception handling in PHP functions
Exception introduction
Exceptions are in PHP Special object representing errors. When a function execution encounters a problem, an exception can be triggered to tell the program that something has gone wrong.
Handling exceptions
Use the try-catch
statement block to handle exceptions:
try { // 可能会触发异常的代码 } catch (Exception $e) { // 处理异常 }
try
Blocks contain code that may trigger exceptions. If an exception occurs, the execution flow jumps to the catch
block.
Exception class
Exception is an object, and its class is a subclass Exception
. PHP provides the following exception classes:
Exception
: General exception ArithmeticError
: Arithmetic error AssertionError
: Assertion failedDivisionByZeroError
: Division by zeroParseError
: Syntax errorPractical Case
The following is a practical case using exception handling:
// 打开一个可能不存在的文件 try { $handle = fopen('myfile.txt', 'r'); } catch (FileNotFoundException $e) { // 文件不存在,显示错误消息 echo '文件 "myfile.txt" 不存在'; }
In this example, the try
block attempts to open a file named "myfile .txt" file. If the file does not exist, it will trigger a FileNotFoundException
exception and the program will jump to the catch
block to handle the exception.
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