JavaScript：数组

1.创建一個数组

<script type="text/javascript">
    //1
    var myArr1 = new Array();
    myArr1[0] = "red";
    myArr1[1] = "green";
    myArr1[2] = "blue";
    console.dir(myArr1);
    //2
    var myArr2 = new Array("red", "blue", "green");
    console.dir(myArr2);
    //3
    var myArr3 = ["red", "green", "blue"];
    console.dir(myArr3);
    //获取元素的索引值
    var y=myArr3.indexOf("blue")   // "blue" 值的索引值
    console.dir(y);

    //==========================For/In 循环
    var txt = "";
    for (x in myArr3)  // x 为属性名
    {
        txt = txt + myArr3[x] + "====";
    }
</script>

2.将数组转换为字符串输出

<script type="text/javascript">
    var myArr = new Array();
    myArr[0] = "red";
    myArr[1] = "green";
    myArr[2] = "blue";
    console.dir(myArr.join());//join()方法
    console.dir(myArr.toString());//toString()方法
</script>

3.删除数组尾部的一个元素，pop()方法

<script type="text/javascript">
    var myArr = ["red", "green", "blue", "qing"];
    function myFun() {
        myArr.pop();//pop()方法
        var x = document.getElementById("mark");
        x.innerHTML = myArr;
    }
</script>
<p id="mark">从数组最后一个元素开始删除</p>
<button type="button" onclick="myFun();">删除</button>

4.在数组尾部添加一个元素，push()方法

<script type="text/javascript">
    var myArr = ["red", "green", "blue", "qing"];
    function myFun() {
        myArr.push("jack");//push()方法
        var x = document.getElementById("mark");
        x.innerHTML = myArr;
    }
</script>
<p id="mark">从数组尾部添加一个元素</p>
<button type="button" onclick="myFun();">添加</button>

5.数组翻转排序，reverse()方法

<script type="text/javascript">
    var myArr = ["red", "green", "blue", "qing"];

    function myFun() {
        myArr.reverse();//reverse()方法
        var x = document.getElementById("mark");
        x.innerHTML = myArr;
    }
</script>
<p id="mark">Here</p>
<button type="button" onclick="myFun();">翻转</button>

6.添加或删除数组，splice()方法

<script type="text/javascript">
    var myArr = ["red", "green", "blue", "qing"];

    function myFun() {
        //myArr.splice(0, 1);//删除索引为0的元素
        myArr.splice(0, 0, "Lemon", "Kiwi");//在索引0的位置上添加
        var x = document.getElementById("mark");
        x.innerHTML = myArr;
    }
</script>
<p id="mark">Here</p>
<button type="button" onclick="myFun();">splice</button>

7.合并数组，concat()方法

<script>
var parents = ["a", "b"];
var brothers = ["s", "d", "b"];
var children = ["c", "l"];
var family = parents.concat(brothers, children);//合并三个数组
document.write(family);
</script>