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docs/note/language/javascript/object_and_class.md

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+# 对象和类
+
+## 对象
+JavaScript中的对象(object)用于存储各种键值集合和更复杂的实体。例如下面的对象
+```javascript :no-line-numbers
+var person = {
+	firstName: 'John',
+	lastName: 'Doe',
+	age: 30,
+	isStudent: false,
+	greet: function() {
+		console.log('Hello, I am ' + this.firstName + ' ' + this.lastName);
+	}
+	print_name() {
+		console.log(lastName + ' ' + firstName) 
+	}
+};
+```
+如何使用对象
+```javascript :no-line-numbers
+console.log(person.firstName);  // 输出: John
+person.greet();  // 输出: Hello, I am John Doe
+```
+
+## 类
+javascript中的类(class)是用于创建对象的模板，和c++中的类相似，但是需要在`constructor()`函数中声明类成员
+```javascript :no-line-numbers
+class User {
+	constructor(name) {
+		this.name = name;
+	}
+
+	greet() {
+		console.log("Hello, I'm " + this.name) 
+	}
+}
+```
+使用方法
+```javascript :no-line-numbers
+var user = new User("Alice")
+user.greet()
+```