1.对象

1.1 字面量创建对象

var teacher = {
    name: '张三',
  age: 32,
  sex: 'male',
  height: 176,
  weight: 130,
  teach: function(){
      console.log('I am teacching JavaScript');
  },
  smoke: function(){
      console.log('I am smoking');
  },
  eating: function(){
      console.log('I am having a dinner');
  }
}
// 查
console.log(teacher.name);
console.log(teacher.weight);
console.log(teacher['height']);
teacher.teach();
// 增加属性和方法
teacher.address = '北京';
teacher.eat = function(){
    console.log('I am having a dinner');
}
consolr.log(teacher);
// 修改属性和方法
teacher.height = 180;
teacher.teach = function(){
    console.log('I am teaching HTML');
}
console.log(teacher);
console.log(teacher.teach);
// 删除属性和方法
delete teacher.address;
// delete teacher.teach(); // 会打印出来,是执行 因为teach() 调用了
delete teacher.taech;
console.log(teacher);

1.2 调用方法从而改变属性值

var teacher = {
    name: '张三',
  age:  32,
  sex: 'male',
  height: 176,
  weight: 130,
  teach: function(){
      console.log('I am teaching JavaScript');
  },
  smoke: function(){
      this. weight--;
    console.log(this.weight);
  },
  eat: function(){
      this.weight++;
    console.log(this.weight);
  }
}
taecher.smoke(); // 129 => taecher.weight: 129
teacher.smoke(); // 128
teacher.eat(); // 129

var attendance = {
    students: [],
  total: 6,
  join: function(name){
      this.students.push(name);
    if(this.students.length === this.total){
        console.log(name + '到课, 学生已到齐');
    }else{
        console.log(name + '到课, 学生未到齐');
    }
  },
  leave: function(name){
      var idx = this.students.indexOf(name);
    if(idx !== -1){
        this.students.splice(idx, 1);
    }
    console.log(name + '早退');
    console.log(this.students);
  },
  classOver: function(){
    console.log('下课了');
    this.students = [];
  }
}
attendance.join('小红');
attendance.join('小王');
attendance.join('小张');
attendance.join('小李');
attendance.join('小刘');
attendance.join('小吴');
attendance.leave('小李');
attendance.classOver();

2. 构造函数创建对象

2.1 系统构造函数创建对象

与对象字面量相等
对象和构造函数是俩码事,对象是通过实例化构造函数而得出的对象实例

// 对象字面量,对象直接量
var obj = {
    name: '张三',
  sex: 'male'
}
// 构造函数,系统自带的Object函数
var obj = new Object();
obj.name = '张三';
obj.sex = 'male';

2.2 自定义构造函数

// // 大驼峰
function Teacher(name, sex, weight, course){
  this.name = name;
  this.sex = sex;
  this.weight = weight;
  this.course = course;
  this.somke = function(){
    this.weight--;
    console.log(this.weight);
  };
  this.eat = function(){
    this.weight++;
    console.log(this.weight);
  }
}
var teacher1 = new Teacher('xiaohong', 'male', 140, 'Java');
var teacher2 = new Teacher('xiaoming', 'male', 150, 'JavaScript');
console.log(teacher1, teacher2);

function Teacher(opt){
  this.name = opt.name;
  this.sex = opt.sex;
  this.weight = opt.weight;
  this.course = opt.course;
  this.somke = function(){
    this.weight--;
    console.log(this.weight);
  };
  this.eat = function(){
    this.weight++;
    console.log(this.weight);
  } 
}
var teacher1 = new Teacher({
  name:'小红',
  sex: 'women',
  weight: 100,
  course: 'JavaScript'
});
var teacher2 = new Teacher({
  name:'小宁',
  sex: 'male',
  weight: 160,
  course: 'Java'
});
console.log(teacher1, teacher2);

3. 练习

1. 写一个构造函数，接收数字类型的参数，参数数量不定，完成参数相加和相乘的功能

 function AddMul(){
      var args = arguments,
          res;
      this.add = function(){
        res = 0;
        loop('add', res);
      }
      this.mul = function(){
        res = 1;
        loop('mul', res);
      }
      function loop(method, res){
        for(var i = 0; i < args.length; i++){
          var item = args[i];
          if(method === 'add'){
            res += item;
          }else if(method === 'mul'){
            res *= item;
          }
        }
        console.log(res);
      }
    }
    var am1 = new AddMul(1, 2, 3, 4);
    am1.add();
    am1.mul();

2. 写一个构造车的函数，可以设置车的品牌，颜色，排量写一个构造消费者的函数，可以设用户的名字，年龄，收入 通过选车的方法，实例化该用户喜欢的车，在设置车的属性

 function Car(opt){
      this.brand = opt.brand,
      this.color = opt.color,
      this.displacement = opt.displacement
      this.myCar = function(){
        console.log(`My car brand is ${this.brand}, color
        is ${this.color}, displacement is ${this.displacement}`);
        console.log(this.displacement);
      }
    }
    function Consumer(user){
      this.name = user.name,
      this.age = user.age,
      this.earning = user.earning,
      this.choiceCar = function(){
        return new Car(user.opt);
      }
    }
    var c1 = new Consumer({
      name: 'xiaomeng',
      age: 16,
      earning: '30K',
      opt:{
        brand: 'benz',
        color: 'white',
        displacement: 3.0
      }
    });
    var car = c1.choiceCar();
    console.log(car);
    car.myCar();