迭代多个数组并执行函数

Question

I have an array with the following structure:

Array
(
    [0] => Array
        (
            [animal] => dog
            [color] => black
        )

    [1] => Array
        (
            [animal] => cat
            [color] => white
        )

    [2] => Array
        (
            [animal] => mouse
            [color] => grey
            [attributes] => Array
                (
                    [nickname] => snuggles
                    [nickname] => buddy
                )

        )

)

I now need to execute a function on every value in the attribute array. So for example capitalize SNUGGLES and BUDDY.

This is my approach:

$array = array(
    array("animal"=>"dog","color"=>"black"),
     array("animal"=>"cat","color"=>"white"),
     array("animal"=>"mouse","color"=>"grey", "attributes" => array("nicknames" => "snuggles", "nicknames" => "buddy"))
);

foreach ( $array as $key => $value ) {
    foreach ( $value as $key1 => $value1 ) {
        if ($key1 == 'attributes') {
            foreach ( $value as $key2 => $value2 ) {
                $value2 =  strtoupper($value2);
                $array [$key] [$key1] [$key2]= $key2;
            }
        }
    }
}

But I get this error:

strtoupper() expects parameter 1 to be string, array given in ...

Answer 1

You are using the wrong variable in your inner loop:

foreach ( $value as $key2 => $value2 ) {
          ^^^^^^ here
    ...
}

Judging by the code, you would want to use $value1 there:

foreach ( $value1 as $key2 => $value2 ) {
          ^^^^^^^ here
    ...
}

Assuming that dropdown => attributes...