php - "&"在 PHP 中是什么意思？

Question

考虑这段 PHP 代码:

call_user_func(array(&$this, 'method_name'), $args);

我知道它在定义函数时意味着按引用传递，但在调用函数时是吗？

Answer 1

来自Passing By Reference文档页面:

You can pass a variable by reference to a function so the function can modify the variable. The syntax is as follows:

<?php
function foo(&$var)
{
    $var++;
}

$a=5;
foo($a);
// $a is 6 here
?>

...In recent versions of PHP you will get a warning saying that "call-time pass-by-reference" is deprecated when you use & in foo(&$a);