I have a function to generate random string,and a program to repeat that function. I want it to generate more than 1 line of random string

I have a Function to generate random string ,and funtion to repeat it .but how to make it generating more than 1 or according to the written in parameter?

    function generatorstring($length = 7){

    $karakter = '0123456789abcdefghijklmnopqrstuvwxyz';
    $randomString = '';
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $karakter[rand(0, strlen($karakter) - 1)];
        }
    return $randomString;
    }
    function repeat($rpt){
        for ($i = 0; $i < $rpt; $i++){
        $res = generatorstring();
        }
    return $res;
    }
    echo repeat(3);

I expected result like this

'As6s8Xs',
'zE71jnM', 
'ak9a71b', 

But, its only produce 1 line of random string.