如何在PHP中创建一个取消指定变量的函数

Question

I'm trying to make a function that takes a variable whether it was set or not,

like the function isset()

//we have this array
$array  = array();
isset($array["test"]);//this one is valid 
myFunc($array["test"]);//this one is not valid 

how can i let my function take not set variables?

Answer 1

Pass the argument as a reference http://php.net/manual/en/language.references.pass.php

function myFunc(&$val)
{
    return isset($val);
}

var_dump(myFunc($undefined));