JavaScript对象属性检查、增加、删除、访问操作实例

var mouse = { "name": "betta", "age": 3, "varieties": "milaoshu"} mouse.hasOwnProperty("name"); // truemouse.hasOwnProperty("sex"); //false

var dog={ name:"芒果", type:"会之王", eat:function(){  alert("吃"); }} Object.prototype.color="白色"; var name; for(name in dog){  document.write(name+" "+dog[name]+"<br>") }

name 芒果type 会之王eat function (){ alert("吃"); }color 白色

var cat = {  "name": "tom",  "sex": "man",  "color": "yellow"}delete cat.name;cat.sex = undefined;cat.color = null;alert("name属性是否存在：" + cat.hasOwnProperty("name")); //falsealert("sex属性是否存在：" + cat.hasOwnProperty("sex")); //truealert("color属性是否存在：" + cat.hasOwnProperty("color")); //true

var cat = {  "name": "tom",  "sex": "man",  "color": "yellow"}var name1 = cat.name; //通过点操作符来访问对象属性var name2 = cat["name"]; //通过中括号操作符来访问对象属性

var obj = new Object();obj.name = "MangGuo";obj.age = 25;var obj = {  name : "MangGuo", //name是属性名，"MangGuo"是值  age : 25}