How to sort following php array with its 'zindex' key value

```
$array = array('the-1'=> array('name'=>'lorem','pos'=>array('top'=>'90','left'=>'80'),'zindex'=>2),
        'the-2'=> array('name'=>'ipsum','pos'=>array('top'=>'190','left'=>'180'),'zindex'=>1),
        'the-3'=> array('name'=>'lorem ipsum','pos'=>array('top'=>'20','left'=>'30'),'zindex'=>3)
        )

```

Is there any php function for getting the output as follows,

```
$array = array(
        'the-2'=> array('name'=>'ipsum','pos'=>array('top'=>'190','left'=>'180'),'zindex'=>1),
        'the-1'=> array('name'=>'lorem','pos'=>array('top'=>'90','left'=>'80'),'zindex'=>2),
        'the-3'=> array('name'=>'lorem ipsum','pos'=>array('top'=>'20','left'=>'30'),'zindex'=>3)
        )

```