How to iterate over function arguments and modify values if null-CodePudding

I want to convert all parameters to empty string when NULL is passed. Something like this, but the original value of the parameters is not changed in my code.

function loopThroughArgs($a, $b) {
    $args = func_get_args();
    foreach ($args as &$arg) {
        $arg = $arg === null ? "" : $arg;
    }
    
    var_dump($a); // should output an empty string
    var_dump($b); // should output an empty string

}

$a = null;
$b = null;

loopThroughArgs($a, $b);

CodePudding user response：

Since func_get_args() returns a copy of those arguments, it won't automatically change your function parameter variables.

You can use get_defined_vars() to reassign values. Loop over all declared variables and assign values to each of them from your $args. If the variable name would have been something different apart from args, that name will come in your if condition.

<?php

function loopThroughArgs($a, $b) {
    $vars = get_defined_vars();
    $args = func_get_args();
    foreach ($args as &$arg) {
        $arg = $arg === null ? "" : $arg;
    }
    
    $ptr = 0;
    
    foreach($vars as $key => $val){
      ${$key} = $args[$ptr  ];
    }
    
    var_dump($a); // should output an empty string
    var_dump($b); // should output an empty string

}

$a = null;
$b = null;

loopThroughArgs($a, $b);

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