在另一个数组的索引之后插入键和值的数组

So I have an array of arrays (of which there is only one) so a multidimensional array. I want to insert more keys and values after each key => value that is currently there. Is there a way to do this?

 $scores= array();
    $scores[] = array('1' => '0', '2' => '83', '3' => '98', '4' => '57', '5' => '0', '6' => '76');

now after each key value, I want to add another that is something like

foreach($scores as $value){
    if(80  >  $value > 69){
        $arrayToAdd = array(
            'hasGrade' = 'true',
            'grade' = 'C'
    }
    if(90  >  $value > 79){
        $arrayToAdd = array(
            'hasGrade' = 'true',
            'grade' = 'B'
    }
    if(100  >  $value > 89){
        $arrayToAdd = array(
            'hasGrade' = 'true',
            'grade' = 'A'
    }
    if($value == 100){
        $arrayToAdd = array(
            'hasGrade' = 'true',
            'grade' = 'A*'
    }
}

I haven't been using php for long and tried googling around but found nothing.

Any help is appreciated!

To solve this you can do something like this :

foreach($scores as $key => $value){
    if($value > 69 && $value < 80){
        $scores[$key]['someNameForYourGradesArray'] = array(
            'hasGrade' = 'true',
            'grade' = 'C'
    }

}

if you don't want 2 levels of arrays, you can simply do :

$scores[$key]['hasGrade'] = 'true';
$scores[$key]['grade'] = 'C';

By the way the true if you want it in boolean, must not be in quotes