检查属性
var mouse = {
"name": "betta",
"age": 3,
"varieties": "milaoshu"
}
mouse.hasOwnProperty("name"); // true
mouse.hasOwnProperty("sex"); //false
增加属性
定义个对象 dog,然后赋予各种特性,再赋予 color特性,最后遍历所有的属性以及值
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>")
}
效果如下
name 芒果
type 会之王
eat function (){ alert("吃"); }
color 白色
删除属性
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")); //false
alert("sex属性是否存在:" + cat.hasOwnProperty("sex")); //true
alert("color属性是否存在:" + cat.hasOwnProperty("color")); //true
访问属性
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
还有创建对象的两种方式
var obj = new Object();
obj.name = "MangGuo";
obj.age = 25;
var obj = {
name : "MangGuo", //name是属性名,"MangGuo"是值
age : 25
}