日期:2014-05-16  浏览次数:20481 次

JS排序问题
怎样实现输入数组 
var arr=new Array(40,20,30);
返回结果
(1,3,2)

即40的在40,20,30中排第一,20的排第三,30排第二。

------解决方案--------------------
JScript code
var arr = new Array(40,20,30);
function sortByNumber(a, b) { return b.v - a.v; }

function mySort(ar) {
    var ar_tmp = [], result = [];
    for (x in ar) ar_tmp.push({k: parseInt(x) + 1, v: ar[x]});
    ar_tmp.sort(sortByNumber);
    for (i in ar_tmp) result.push(ar_tmp[i].k);
    return result;
}
alert(mySort(arr)); //1,3,2

------解决方案--------------------
JScript code

var arr = new Array(40,20,30);
var a = [];
var b = [];
for(var i in arr) a.push({"idx":i, "val":arr[i]});
a.sort(function(x, y){
    return y.val - x.val;
});
for(var i in a) a[i].pos = parseInt(i,10)+1;
a.sort(function(x, y){
    return x.idx - y.idx;
})

for(var i in a) b.push(a[i].pos);
alert(b.join(","))

------解决方案--------------------
HTML code

<!DOCTYPE HTML>
<html>
    <head>
        <meta charset="gb2312" />
        <title></title>
    </head>
    <body>
        <script>
            Array.prototype.clone = function(){
                var tmp = [];
                for(var i = 0, len = this.length; i < len; i++){
                    tmp.push(this[i]);
                }
                return tmp;
            }
            Array.prototype.find = function(val){
                for(var i = 0, len = this.length; i < len; i++){
                    if( this[i] === val ){
                        return i;
                    }
                }
                return -1;
            }            
            var arr = [40, 20, 30, 15, 8, 76];
            var tmp = arr.clone().sort(function(a, b){return b - a;})
            var re = [];
            for(var i = 0, len = arr.length; i < len; i++){
                re.push(tmp.find(arr[i])+1);
            }
            alert(re);
        </script>
    </body>
</html>

------解决方案--------------------
JScript code

> var arr = [40, 20, 30];
undefined
> var result = [1,2,3];
undefined
> result.sort(function(a, b) { return arr[b-1]-arr[a-1];});
[ 1, 3, 2 ]