摘要：普通寫法轉換過程先變型盡量不要出現函數嵌套函數可以有全局變量把中不是賦值的語句放到多帶帶函數中改成面向對象全局變量就是屬性函數就是方法中創建對象改指向事件或定時器問題現要求再創建一個選項卡，自動輪播，只需新增修改和新增一個方法

html:

    
    
    
    
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css:

#div1 div{width: 200px; height: 200px;border:1px #000 solid; display: none;}
.active{background:#f00;}

js:

// 普通寫法

    window.onload = function () {
        var oParent = document.getElementById("div1");
        var aInput = oParent.getElementsByTagName("input");
        var aDiv = oParent.getElementsByTagName("div");
        for (var i = 0; i < aInput.length; i++) {
            aInput[i].index = i;
            aInput[i].onclick = function () {
                for (var i = 0; i < aInput.length; i++) {
                    aInput[i].className = "";
                    aDiv[i].style.display = "none"
                }
                this.className = "active";
                aDiv[this.index].style.display = "block"
            }
        }
    }
    

轉換過程
-先變型 盡量不要出現函數嵌套函數,可以有全局變量,把onload中不是賦值的語句放到多帶帶函數中

    var oParent = null;
    var aInput = null;
    var aDiv = null;
    window.onload = function () {
        oParent = document.getElementById("div1");
        aInput = oParent.getElementsByTagName("input");
        aDiv = oParent.getElementsByTagName("div");
        init();
    }

    function init() {
        for (var i = 0; i < aInput.length; i++) {
            aInput[i].index = i;
            aInput[i].onclick = change;
        } 
    }

    function change() {
        for (var i = 0; i < aInput.length; i++) {
            aInput[i].className = "";
            aDiv[i].style.display = "none"
        }
        this.className = "active";
        aDiv[this.index].style.display = "block"
    }
    

//改成面向對象
全局變量就是屬性 函數就是方法 onload中創建對象 改this指向(事件或定時器問題)

    window.onload = function () {
       var t1 = new Tab()
       t1.init();
    }
    function Tab() {
        this.oParent = document.getElementById("div1");
        this.aInput = this.oParent.getElementsByTagName("input");
        this.aDiv = this.oParent.getElementsByTagName("div");
    }
    Tab.prototype.init = function () {
        var This = this;
        for (var i = 0; i < this.aInput.length; i++) {
            this.aInput[i].index = i;
            this.aInput[i].onclick = function (){
                This.change(this);
            }
        } 
    }
    Tab.prototype.change = function (obj) {
        for (var i = 0; i < this.aInput.length; i++) {
            this.aInput[i].className = "";
            this.aDiv[i].style.display = "none"
        }
        obj.className = "active";
        this.aDiv[obj.index].style.display = "block"
    }
    

現要求再創建一個選項卡，自動輪播，只需新增div2 修改init和新增一個autoPlay方法

    window.onload = function () {
       var t1 = new Tab("div1")
       t1.init();
       var t2 = new Tab("div2")
       t2.init();
       t2.autoPlay();
    }
    function Tab(id) {
        this.oParent = document.getElementById(id);
        this.aInput = this.oParent.getElementsByTagName("input");
        this.aDiv = this.oParent.getElementsByTagName("div");
        this.iNow = 0;
    }

    Tab.prototype.autoPlay = function () {
        var This = this;
        setInterval(function () {
            if(This.iNow == This.aInput.length-1) {
                This.iNow = 0;
            }else {
                This.iNow++;
            }
            for (var i = 0; i < This.aInput.length; i++) {
                This.aInput[i].className = "";
                This.aDiv[i].style.display = "none"
            }
            This.aInput[This.iNow].className = "active";
            This.aDiv[This.iNow].style.display = "block"
        }, 2000)
    }