我想在保留数组键的同时合并两个 arrays

Question

I want to merge two arrays while keeping the array keys

I want to create $array_true merging $array_1 and $array_2 as follows.

$array_1 = array(
    'some_one' => 'some_text',
    'array_1'  => array(
        'value_1_1',
        'value_1_2'
    ),

);

$array_2 = array(
    'some_one' => 'some_text_2',
    'array_0'  => array(
        'value_0_1',
        'value_0_2'
    ),
    'array_1'  => array(
        'value_defaults_1_1',
        'value_defaults_1_2'
    ),
    'array_2'  => array(
        'value_defaults_2_1',
        'value_defaults_2_2'
    ),
);

// Ultimately, I would like to create such a function.
$array_true = array(
    'some_one' => 'some_text',
    'array_0'  => array(
        'value_0_1',
        'value_0_2'
    ),
    'array_1'  => array(
        'value_1_1',
        'value_1_2'
    ),
    'array_2'  => array(
        'value_defaults_2_1',
        'value_defaults_2_2'
    ),
);

function my_merge_func($array_1, $array_2) {
    $merged = $array_1;
    foreach ($array_2 as $key => $value) {
        if (
            empty($array_1[ $key ])
        ) {
            $merged[ $key ] = $value;
        } else if(is_array($value) && is_array($array_1[ $key ])) {
            $merged[ $key ] = my_merge_func($array_1[ $key ], $value);
        }
    }
    return $merged;
}
var_dump(my_merge_func($array_1,$array_2));

var_dump($array_true);

var_dump(my_merge_func($array_1,$array_2) ===  $array_true);

my_merge_func will be the one I created in the previous question

Functions like array_merge with recursive processing

As it is now, the array looks like this.

array(4) {
  ["some_one"]=>
  string(9) "some_text"
  ["array_1"]=>
  array(2) {
    [0]=>
    string(9) "value_1_1"
    [1]=>
    string(9) "value_1_2"
  }
  ["array_0"]=>
  array(2) {
    [0]=>
    string(9) "value_0_1"
    [1]=>
    string(9) "value_0_2"
  }
  ["array_2"]=>
  array(2) {
    [0]=>
    string(18) "value_defaults_2_1"
    [1]=>
    string(18) "value_defaults_2_2"
  }
}

I would appreciate your advice.

Answer 1

The issue isn't with the function you've created; that works exactly like it should. The problem is your very last line of code:

var_dump(my_merge_func($array_1,$array_2) ===  $array_true);

Of course, you'd just like to check whether the resulting array matches your desired result. If you have a look at the PHP manual for the array comparison operators, you'll read the following for the triple equals ( === ) operator:

true if $a and $b have the same key/value pairs in the same order and of the same types.

While all of your value pairs have the exact same key/value-pairs and types, the order is not the same, which is why the === returns false. Functionally, the arrays are exaclty the same and the order does not matter at all. The quick fix is to change to a double equals:

var_dump(my_merge_func($array_1,$array_2) == $array_true);

It doesn't account for type safety, but it does the trick for this application.