php - explode string into variables

Question

Is there a way to explode a string into variables e.g

some_function($min, $max, "3, 20");

such that $min is assigned the value 3 and $max is assigned the value 20.

I know I can simply use

$data = explode("3, 20");

just wondering if there is another way.

Answer 1

PHP's language construct list() can perform multiple assignments to variables (or even other array keys) by assigning an array.

list($min, $max) = explode(",", "3,20");

However, you would still need to apply a trim() to your variables since the $max value would have a leading space, or replace explode() with preg_split('/s*,s*/', $string) to split it on commas and surrounding whitespace.

Note: Use caution with list() to be sure that the array you're assigning contains the same number of elements as list() has variables.

In PHP 5.x, when assigning a value directly to another array, as an element of that array, list() values are assigned from right to left in PHP 5.x, not left to right. In other words, you'll end up with array that is populated backwards (last value, first).

https://www.php.net/manual/en/migration70.incompatible.php

In PHP 7.x list() arguments are assigned from left to right, when assigning elements directly to an array. In other words, you'll end up with the first value as the first element in the recipient array.

<?php
    list($a[], $a[], $a[]) = [1, 2, 3];
    var_dump($a);
?>

PHP Manual

PHP 5.X Last value gets the first element position, but the recipient must an array (in this case $a, is the array)!

array(3) {
  [0]=>
  int(3)
  [1]=>
  int(2)
  [2]=>
  int(1)
}

PHP 7.x First value becomes the first array element.

array(3) {
  [0]=>
  int(1)
  [1]=>
  int(2)
  [2]=>
  int(3)
}

PHP Manual