PHP 7 改变了大多数错误的报告方式。不同于传统（PHP 5）的错误报告机制，现在大多数错误被作为 Error 异常抛出。
这种 Error 异常可以像 Exception 异常一样被第一个匹配的 try / catch 块所捕获。如果没有匹配的 catch 块，则调用异常处理函数（事先通过 set_exception_handler() 注册）进行处理。 如果尚未注册异常处理函数，则按照传统方式处理：被报告为一个致命错误（Fatal Error）。
Error 类并非继承自 Exception
类，所以不能用 catch (Exception $e) { ... } 来捕获
Error。你可以用
catch (Error $e) { ... }，或者通过注册异常处理函数（
set_exception_handler()）来捕获 Error。
<?php
set_error_handler(function(int $number, string $message) {
echo "Handler captured error $number: '$message'" . PHP_EOL ;
});
try {
echo $x; # notice, handled on callable
pg_exec(null, null); # warning, handled on callable
fho(); # fatal error, stop running and catched
} catch (Throwable $e) {
echo "Captured Throwable: " . $e->getMessage() . PHP_EOL;
}
?>
set_error_handler will also works without try and catch
An excellent blog post on the difference between exceptions, throwables and how PHP 7 handles these can be found here: https://trowski.com/2015/06/24/throwable-exceptions-and-errors-in-php7/
php 7.1
try {
// Code that may throw an Exception or ArithmeticError.
} catch (ArithmeticError | Exception $e) {
// pass
}
Throwable does not work on PHP 5.x.
To catch both exceptions and errors in PHP 5.x and 7, add a catch block for Exception AFTER catching Throwable first.
Once PHP 5.x support is no longer needed, the block catching Exception can be removed.
try
{
// Code that may throw an Exception or Error.
}
catch (Throwable $t)
{
// Executed only in PHP 7, will not match in PHP 5
}
catch (Exception $e)
{
// Executed only in PHP 5, will not be reached in PHP 7
}
You can catch both exceptions and errors by catching(Throwable)