js 获取对象属性个数
方法一:
var attributeCount = function(obj) {var count = 0;for(var i in obj) {if(obj.hasOwnProperty(i)) { // 建议加上判断,如果没有扩展对象属性可以不加count++;}}return count;}var testObj = {name1: "value1",name2: "value2"};alert(attributeCount(testObj)); // 2
方法二:
function TestObj(name, age) {this.name = name,this.age = age}TestObj.prototype.proCount = function() {var count = 0for(pro in this) {if(this.hasOwnProperty(pro)) { // 这里扩展了对象,所以必须判断count++;}}return count;}var testObj = new TestObj('名称', 12);alert(testObj.proCount()); // 2
方法三:
var testObj = {name1: "value1",name2: "value2"};alert(Object.getOwnPropertyNames(testObj).length); // 2
