javascript 判断对象是否为空

javascript 判断对象是否为空

function is_empty(obj) {
  "use strict";
  if (Object.prototype.toString.call(obj) === '[object Object]') {
    // Assume if it has a length property with a non-zero value
    // that that property is correct.
    if (obj.length && obj.length > 0){ return false; }
    if (obj.length && obj.length === 0){return true; }
    for (var key in obj) {
      if (Object.prototype.hasOwnProperty.call(obj, key)) { return false; }
    }
  } else if (Object.prototype.toString.call(obj) === '[object Array]') {
    if (obj.length && obj.length > 0){ return false; }
  }
  return true;
}