JavaScript object basics
Object
##The concept of object
Object classification in JS
This chapter focuses on JS built-in objects and simple Custom objects, BOM objects and DOM objects, we will introduce them in detail in the following chapters
##Custom object
This chapter only gives a brief introduction
1. Use the new keyword combined with the constructor Object() to Create an empty object
<!DOCTYPE HTML> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>php.cn</title> <script> //使用new关键字结合构造函数Object()来创建一个空的对象 var info = new Object(); //增加属性 info.name = "张三"; info.age = 20; //增加方法:将一个函数定义赋值给了对象属性,这时,对象属性变成了方法 info.show=function(){ var str="我叫"+info.name+"今年已经"+info.age+"岁了"; return str; } //调用对象方法,并输出结果 document.write(info.show()); </script> </head> <body> </body> </html>2. Use braces {} to create an object
<!DOCTYPE HTML> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>php.cn</title> <script> //使用大括号{}来创建对象 var info = { //增加属性 name :"张三", age : 20, //增加方法:将一个函数定义赋值给了对象属性,这时,对象属性变成了方法 show:function(){ var str="我叫"+info.name+"今年已经"+info.age+"岁了"; return str; } } //调用对象方法,并输出结果 document.write(info.show()); </script> </head> <body> </body> </html>
JS built-in object
- Array object: Array object provides properties and methods for array operations.
- Date object: Date and time object, which can obtain the date and time information of the system.
- Boolean object: Boolean object, a Boolean variable is a Boolean object. (No properties and methods available)
- Number object: Numeric object. A numeric variable is a numeric object.
- Math object: Mathematical object, which provides properties and methods for mathematical operations.
- Let’s introduce each built-in object in detail