push to array recursively

recursivePush.js

function recursivePush(arr, val) {
  var execPush = false;
  arr.forEach(function(_v) {
    if(_v instanceof Array) {
      recursivePush(_v, val);
    } else {
      execPush = true;
    }
  });
  if(execPush || !arr.length) { arr.push(val); };
}