array_replace和array_replace_recursive之间有所不同

Question

Hi I am having a difficult to understand the difference between these two function in php array_replace and array_replace_recursive.

array array_replace_recursive ( array $array1 , array $array2 [, array $... ] )

and

array array_replace ( array $array1 , array $array2 [, array $... ] )

and thanks in advance

Answer 1

The difference arises when you have arrays within arrays. Taking from here, let's create two arrays:

$base = array('citrus' => array( "orange") , 
              'berries' => array("blackberry", "raspberry"), 
             );
$replacements = array('citrus' => array('pineapple'), 
                      'berries' => array('blueberry')
                );

If we do

$basket = array_replace($base, $replacements);

We will get

Array
(
[citrus] => Array
    (
        [0] => pineapple
    )

[berries] => Array
    (
        [0] => blueberry
    )

)

where the array "blueberry" has replaced the array "blackberry","raspberry". If instead we do

$basket = array_replace_recursive($base, $replacements);

we will get

Array
(
[citrus] => Array
    (
        [0] => pineapple
    )

[berries] => Array
    (
        [0] => blueberry
        [1] => raspberry
    )

)

Now the first element in the array "blueberry" has replaced the first element in the array "blackberry","raspberry". So it's an array replacement within an array replacement, or a recursive replacement.