在JavaScript中,引用类型是一种数据结构,用于将数据和功能组织在一起。
对象是某个特定引用类型的实例。对象的创建方式:
var person = new Object();
上面的例子创建了Object引用类型的一个新实例,然后把该实例保存在变量person中。
创建对象有构造函数和对象字面量两种方式。
1.构造函数方式
使用new操作符后跟Object构造函数。
var p = new Obejct(); p.name = "萧萧弈寒"; p.age = 18;
2.对象字面量方式
对对象定义的一种简写,目的在于简化创建包含大量属性的对象的过程。示例:
var p = { name:"萧萧弈寒", age:18 };
在对象字面量语法时,属性名也可以使用字符串,例如:
var p = { "name":"萧萧弈寒", "age":18, 5:true }
上面的例子会创建一个对象,包含name、age、5三个属性。这里的数值属性名会自动转换为字符串。
另外,使用对象字面量语法时,如果留空其花括号,则可以定义包含默认属性和方法的对象。例如:
var p = {}; p.name = "萧萧弈寒"; p.age = 18;
一般来说,访问对象的属性使用的是点表示法,在JavaScript也可以使用方括号表示法来访问对象的属性。在使用方括号语法时,应该将要访问的属性以字符串的形式放在方括号中,例如:
alert(p["name"]); alert(p.name);
功能上这两种访问方式没什么区别。方括号语法的优点是可以通过变量来访问属性:
var propName = "name"; alert(p[propName]); // "萧萧弈寒"
如果属性名中包含关键字或保留字等会导致错误的字符,也可以使用方括号表示法。例如:
p["first name"] = "萧萧弈寒";
属性first name中包含一个空格,不能通过点表示法访问。
以上这篇深入剖析JavaScript:Object类型就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持脚本之家。

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JavaScript is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.

Python is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.

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