PHP read txt file to read a random line

Why 80% of the code can not do farming architect? >>>  

function rarray_rand( $arr ){
    return mt_rand( 0, count( $arr ) - 1 );
}
function varray_rand( $arr ) {
    return $arr[rarray_rand($arr)];
}

$key  = file("./key.txt");
$keyword=trim(varray_rand($key));

Reproduced in: https: //my.oschina.net/johnfu/blog/206918