<script>
    var arr = (1,2,3,[4,5,6],{}); //其中数组元素可以是number，string，object
    console.log(arr);//在控制台输出数组</script>

<script>var arr = new Array[1,2,3,[4,5,6],{}];
console.log(arr);

<script>
    var arr = [1,2,3,4,"A"];
    arr[5] = "M"; //如果为数组元素赋值的索引i大于数组长度，则添加数组元素后的数组长度为 i+1
    console.log(arr);</script>

<script>
    var arr = [1,2,3,4,"A"];
    arr.push("BB","cc");//在数组元素的后面添加，可以追加多个元素，
    console.log(arr);</script>

<script>
    var arr = [1,2,3,4,"A"];
    arr.unshift("BB","cc");//在数组元素的前面添加，可以追加多个元素，
    console.log(arr);</script>

<script>
    var arr = ["A", "B", "C", "D"];
    arr.pop(); //删除最后一个元素，没有参数，每次只能删除一个
    console.log(arr);</script>

<script>
    var arr = ["A", "B", "C", "D"];
    arr.shift(); //删除第一个数组元素，没有参数，每次只能删除一个
    console.log(arr); </script>

 <script>
    var arr = ["A", "B", "C", "D"];
    arr[2] = "E";
    console.log(arr); </script>

<script>
    var arr = ["A", "B", "C", "D"];
    console.log(arr.length);    for(var i = 0; i<arr.length;i++){
        console.log(arr[i]);
    }</script>

   <script>
        var arr = [
            [1, 2, 3],
            [4, 5, 6],
            [7, 8, 9]
        ]        for(var i = 0;i<arr.length;i++){ //先遍历arr
            for(var j = 0;j<arr[i].length;j++){ //遍历arr元素中的数组元素
                console.log(arr[i][j]);
            }
        }    </script>

 <script>    
 var arr = ["A","B","C","D"]    var a = arr.join("*")    console.log( a);    
 var a = arr.join("+")    console.log( a);    var a = arr.join("-")    console.log( a);    
 var a = arr.join("/")    console.log(a);    console.log(typeof a);
</script>

  <script>
      var arr = ["A","B","C","D"]      
      var a = arr.reverse();  //倒置数组顺序
      for(var i = 0; i< arr.length; i++) //遍历数组
      {
        console.log(a[i]);
      }      
    </script>

 <script>
     var arr = ["A","B","C","D"];     
     var arr1 = ["A","B","C","D"];     
     var arr2 = ["A","B","C","D"];     
     var arr3 = ["A","B","C","D" ,[1,2,3]];     
     var a = arr.concat(arr1,arr2,arr3) //concat将多个数组拼接成一个数组,其中的多维数组是不会展开的 
     console.log(a);
     console.log(typeof a)  
    </script>

 <script>
       var arr = ["d","AbC","AaC","D",1,8,6];       
       var a = arr.sort(); //sort是单个字符比较 例如AbD和AaC 先比较第一个字母，在比较第二个字母，第二个字母那个小就排在前面，之后就不比较后面的字母大小了
       console.log(a);    </script>

   <script>
         var arr = ["A","B","C","D"];         
         var a = arr.slice(1,3); //截取的元素包括开始截取的元素，但是不包括最后截取的元素
         console.log(a);         
         var a = arr.slice(1); //只写一个则表示截取到最后一个元素
         console.log(a);    </script>

<script>
      var arr = ["A","B","C","D"];      
      var a = arr.toString();
      console.log(a);
      console.log(typeof a);    
 </script>