Javascript basic concept.....

我們提供的服務(wù)有：網(wǎng)站制作、做網(wǎng)站、微信公眾號開發(fā)、網(wǎng)站優(yōu)化、網(wǎng)站認(rèn)證、黃島ssl等。為上1000+企事業(yè)單位解決了網(wǎng)站和推廣的問題。提供周到的售前咨詢和貼心的售后服務(wù)，是有科學(xué)管理、有技術(shù)的黃島網(wǎng)站制作公司

[@more@]

• Instance property: property defined in constructor:

  function Circle(radius) {
  	this.radius = radius;	
  }
  

• Class property: property belongs to class. all instances share the only copy of class property:

  Circle.PI = 3.141592;
  Circle.UNIT = new Circle(1);
  	
  	

• Instance method:An instance method can be invoked for any instance of a class, but this does not mean that each object contains its own private copy of the method, as it does with instance properties.Instead, instance method is defined by prototype property:

  Circle.prototype.area() { // notes: must explicitly specify thiskeyword to property
  	return Circle.PI * this.radius * this.radius;
  }
  	

• Class method: method associated with a class rather than an instance of a class:

  Circle.max = function (a,b) {
  	if (a.r > b.r) {
  		return a;
  	}else {
  		return b;
  	}
  }
  

---

Function execute & Call Object Concept

When Invoke a function, the function scope is set to scope chain, and then add a new object known as call object to the front of the scope chain. the call object is initialized with parameters, local variable. If a nested function is invoked, the scope chain includes three objects: its own call object, the call object of outer object , and the global object.

uniqueID = function(){ // user can set id back to 0 by: uniqueID.id = 0
    if (!arguments.callee.id) 
        arguments.callee.id = 0;
    return arguments.callee.id++;
};

uid = (function(){ // closure, id is persistent and private
    var id = 0;
    return function(){
        return id++;
    };
})();

var ret = "";
var i = 10;

while (i--) {
    ret += uniqueID() + "t";
    uniqueID.id = 0;
}
alert(ret);

i = 10;
ret = "";
while (i--) {
    ret += uid() + "t";
}
alert(ret);

文章題目：JavascriptStudyMemo
轉(zhuǎn)載源于：http://jinyejixie.com/article10/ggsgdo.html

成都網(wǎng)站建設(shè)公司_創(chuàng)新互聯(lián)，為您提供移動網(wǎng)站建設(shè)、網(wǎng)站設(shè)計(jì)、企業(yè)建站、App開發(fā)、網(wǎng)站制作、用戶體驗(yàn)

廣告

聲明：本網(wǎng)站發(fā)布的內(nèi)容（圖片、視頻和文字）以用戶投稿、用戶轉(zhuǎn)載內(nèi)容為主，如果涉及侵權(quán)請盡快告知，我們將會在第一時間刪除。文章觀點(diǎn)不代表本網(wǎng)站立場，如需處理請聯(lián)系客服。電話：028-86922220；郵箱：631063699@qq.com。內(nèi)容未經(jīng)允許不得轉(zhuǎn)載，或轉(zhuǎn)載時需注明來源： 創(chuàng)新互聯(lián)