【JS】(+﹏+)~

1

var o = new Object()
var o = new Object // 如果没有参数，括号可以省略

2

this.init.apply(this, arguments) ???

// 创建类
var Class = function() {
    var klass = function() {
        this.init.apply(this, arguments)
    }
    klass.prototype.init = function() {}
    return klass
}

var Person = new Class()
Person.prototype.init = function() {
}

var person = new Person()

what does this usage of apply() means in Javascript

;(function() {
    var Klass = function(arg1, arg2, arg3) {
        this.init(arg1, arg2, arg3)
    }
    Klass.prototype.init = function(arg1, arg2, arg3) {
        console.log(arg1, arg2, arg3)
    }
    var klass = new Klass(1, 2, 3)
})()

;(function() {
    var Klass = function() {
        this.init.apply(this, arguments)
    }
    Klass.prototype.init = function() {
        console.log(arguments[0], arguments[1], arguments[2])
    }
    var klass = new Klass(1, 2, 3)
})()

;(function() {
    var Klass = function() {
        this.init(arguments[0], arguments[1], arguments[2])
    }
    Klass.prototype.init = function() {
        console.log(arguments[0], arguments[1], arguments[2])
    }
    var klass = new Klass(1, 2, 3)
})()

3

/**
 * 当你读取一个对象的属性时，JS首先会在本地对象中查找这个属性，
 * 如果没有找到，JS开始在对象的原型中查找，
 * 仍未找到还会继续查找原型的原型，
 * 直到查找到Object。prototype
 * 如果找到这个属性，则返回这个值，否则返回undefined
 */
var Person = function() {
    this.say = function() {
        console.log('e')
    }
}
Person.prototype.say = function() {
    console.log('ee')
}
new Person().say() // e