flatten a JavaScript array

flatten.js

function flatten(arr) {
  var result = [];
  for(var i = 0, length = arr.length; i < length; i ++ ){
    var value = arr[i];
    if(!Array.isArray(value)){
      result.push(value); 
    } else {
     result = result.concat(flatten(value));//递归调用
    }
  }
  return result;
}
console.log(flatten([1,[2,3,[4,5,6,[2,[23232,[323,232,[232]]]]]]]));