Merge "Defaults" array with "Input" array? PHP Which Function?

Question

Lets say you are having a user provide information.

Array 1

But not all is required. So you have defaults.

Array 2

Does PHP have a function which will overwrite all array values of Array 2 based on if they are supplied in Array 1, and not empty?

Answer 1

If you just want to keep the options that you expect and discard the rest you may use a combination of array_merge and array_intersect_key.

<?php

function foo($options) {
    $defaults = [
        'a' => 1,
        'b' => null,
    ];

    $mergedParams = array_merge(
        $defaults,
        array_intersect_key($options, $defaults)
    );

    return $mergedParams;
}


var_dump(foo([
    'a' => 'keep me',
    'c' => 'discard me'
]));

// => output
//
// array(2) {
//   ["a"]=>
//   string(7) "keep me"
//   ["b"]=>
//   NULL
// }

If you instead want to keep any extra key then array_merge($defaults, $options) will do just fine.

Answer 2

$defaults = array(
    'some_key_1'=>'default_value_1',
    'some_key_2'=>'default_value_2',
);

$inputs = array_merge($defaults, $inputs)

Note that if the $inputs array contains keys not in the $defaults array they will be added in the result.