JavaScript adds properties and methods to objects
JavaScript can define properties and methods when defining a class, or dynamically add properties and methods after creating an object.
Dynamic addition of properties and methods is difficult to achieve in other object-oriented programming languages ????(C++, JavaScript, etc.), which is a reflection of the flexibility of JavaScript.
Create an object based on the Person class and add properties and methods to it: // Define class
<script>// 定義類
function Person(name,sex) {
this.name=name; // 定義一個屬性 name
this.sex=sex; // 定義一個屬性 sex
this.say=function(){ // 定義一個方法 say()
return "嗨！大家好，我的名字是 " + this.name + " ，性別是 " + this.sex + " 。";
}
}
// 創(chuàng)建對象
var zhangsan=new Person("張三","男");
zhangsan.say();
// 動態(tài)添加屬性和方法
zhangsan.tel="029-81892332";
zhangsan.run=function(){
return " 我跑得很快！ ";
}
// 彈出警告框
alert("姓名："+zhangsan.name);
alert("姓別："+zhangsan.sex);
alert(zhangsan.say());
alert("電話："+zhangsan.tel);
alert(zhangsan.run());</script>
