//求数组的元素和

1     var arr = [2,6,1,7,4];
2 
3   var num = 0;
4   for(var i = 0;i < arr.length;i++){
5     console.log(arr[i]);
6     var num = num + Number(arr[i]);
7   }
8   console.log(num);

////////将1~10存到数组里面

1 var arr = [];
2   for (var i = 0;i < 10;i++){
3       arr[i] = i + 1;
4   }
5   console.log(arr);

//在一个数组中挑选出大于10的数字放到另外的数组中

 1  var oldarr = [2.5,7,11,8,22,33,6,66];
 2   var newarr = [];
 3   var j = 0;
 4   for (var i = 0;i < oldarr.length;i++){
 5       if (oldarr[i] > 10){
 6           newarr[j] = oldarr[i];
 7           j++;
 8       }
 9   }
10   console.log(newarr);

//找出数组中最大值的案例

 1  var max = 0;
 2   var arr = [2,6,1,77,52,25,7];
 3   var max = arr[0];
 4   for(var i = 1;i <= arr.length;i++){
 5 
 6       if(arr[i] > max){
 7            max = arr[i];
 8       }
 9   }
10   console.log(max);