JavaScript启示录阅读笔录

//创建copy对象
var copy = new Object();

//为对象的各种属性赋值
copy.living = true;
copy.age = 33;
copy.gender = 'male';


// logs Object {living = true, age = 33, gender = 'male'}
console.log(cody); 

//Pserson是一个构造函数 使用new关键字进行实例化
  var Person = function(living,age,gender){
        //this表示即将创建的新对象
        
        this.living = living;
        this.age = age;
        this.gender = gender;
        this.getGender = function(){
            return this.gender;
        }
        
    //实例化Person对象 
    var copy = new Person(true,22,'male');
    
    console.log(copy.constructor);//输入Person函数
  }

var number = new Number(22);
var string = new String("male");
var boolean = new Boolean(false);
var obj = new Object();
var arr = new Array("foo","dfa");
var func = new Function("x","y","return x*y");
var date = new Date();
var reg = new RegExp('\bt[a-z]+\b');
var error = new Error("Crap");

//使用对象封装，创建对象链
var obj1 = {
    obj1_1: {
        obj1_1_1: {}
    },
     obj1_2: {
        obj1_2_1: {}
    },
};

//使用数组封装 创建多维数组链

var myArr = [ [ [] ] ];

//使用function封装

var myFunc = function(){

    va myfunc = function(){
        var myfunc = function(){
            
        }
    }
}

// creating cody Object() object
var cody = new Object();

// setting properties
cody['living'] = true;
cody['age'] = 33; 
cody['gender'] = 'male';
cody['getGender'] = function() {return cody.gender;};

// getting properties
console.log(
    cody['living'], 
    cody['age'], 
    cody['gender'], 
    cody['getGender']() // just slap the function invocation on the end!
); // logs 'true 33 male male'

// updating properties, very similar to setting
cody['living'] = false;
cody['age'] = 99; 
cody['gender'] = 'female';
cody['getGender'] = function() {return 'Gender = ' + cody.gender;};

var foo = {bar:"bar"};
delete foo.bar;

console.log("bar" in foo);

var obj = {foo:"value"};
console.log(obj.hasOwnProperty("foo"));//true

var myObject = {foo: 'value'};
console.log('foo' in myObject); // logs true

var copy = {
    age:23,
    gender:'male'
};

for(var key in copy){//key表示每个属性的名称
    if(copy.hasOwnproperty(key)){ //避免来自原型链的属性
        console.log(key);
    }
}

var copy = {};
for (key in copy){
    if(copy.hasOwnproperty(key)){
        console.log(key);
    }
}

var add = function(){

    return arguments[0] + arguments[1];
};

console.log(add(4,4));//8

var myObject1 = {
    name: 'myObject1',
    myMethod: function(){console.log(this.name);}
};

myObject1.myMethod(); // logs 'myObject1'

var myObject2 = function(){console.log(this);}; 

myObject2(); // logs Window

var myObject1 = {
    name: 'myObject1',
    myMethod: function(){console.log(this.name);}
};

myObject1.myMethod(); // logs 'myObject1'

var myObject2 = function(){console.log(this);}; 

myObject2(); // logs Window

var myFunction = function(z, s, d, e, r, m, q) {
    return myFunction.length;
};

console.log(myFunction()); //logs 7

//函数构造函数
var addConstructor = new Function("x","y","return x + y");

//函数语句
function  addStatement(x,y){
    return x + y;
}

//函数表达式
var addExp = function(){
    return x + y;
}

var cody = {
    living : true,
    age : 23,
    gender : 'male',
    getGender : function() {return cody.gender;}
};

console.log(cody.getGender()); // logs 'male'

var cody = {
    living: true, 
    age: 23, 
    gender: 'male', 
    getGender: function() {return this.gender;}
};

console.log(cody.getGender()); // logs 'male'