JavaScript創(chuàng)建對(duì)象
JavaScript 提供了一些常用的內(nèi)置對(duì)象(稍后介紹),但是有些情況下我們需要自定義地創(chuàng)建對(duì)象,以達(dá)到特殊的、豐富的功能。
比如我們創(chuàng)建一個(gè)“student”對(duì)象,并為其指定幾個(gè) 屬性 和 方法:
student = new Object(); // 創(chuàng)建對(duì)象“student” student.name = "Tom"; // 對(duì)象屬性 名字 student.age = "19"; // 對(duì)象屬性 年齡 student.study =function() { // 對(duì)象方法 學(xué)習(xí) alert("studying"); }; student.eat =function() { // 對(duì)象方法 吃 alert("eating"); };
此外,你也可以這樣創(chuàng)建對(duì)象:
var student = {}; student.name = "Tom"; ……
或者這樣:
var student = { name:"Tom"; age:"19"; …… }
但是以上方法在創(chuàng)建多個(gè)對(duì)象時(shí),會(huì)產(chǎn)生大量重復(fù)代碼,所以我們也可以采用函數(shù)的方式新建對(duì)象:
function student(name,age) { this.name = name; this.age = age; this.study = function() { alert("studying"); }; this.eat = function() { alert("eating"); } }
然后通過(guò) new 創(chuàng)建 student 對(duì)象的實(shí)例:
var student1 = new student('Tom','19'); var student2 = new student('Jack','20');
<!DOCTYPE html> <html> <body> <script> person={firstname:"Bill",lastname:"gates",age:56,eyecolor:"blue"} document.write(person.firstname + " is " + person.age + " years old."); </script> </body> </html>