如何使用递归修改数组

Question

I have array

$arr = ['one', 'two', 'free'];
$value = 10;

Need use recursion function.

So I wanna get array like this

$result = ['one' => ['two' => ['free' => 10]]];

Answer 1

You can loop the array in reverse and build the array from the furthest nested value and back.

$arr = ['one', 'two', 'free'];
$value = 10;

$arr = array_reverse($arr);

foreach($arr as $key => $val){
    if($key==0){
        $new[$val]= $value;
    }else{
        $new = [$val => $new]; //this overwrites the array with a new array with another layer
    }
}

var_dump($new);

https://3v4l.org/VRJOY