javascript数组多字段排序-蒲公英云

javascript数组多字段排序

对于需要多字段排序的数组，我们可以借用javascript的原生数组api来完成，

这个api就是sort方法。

arr.sort(sortby)

这个方法的sortby参数可选，这个参数是一个回调方法。

参数：该方法有两个参数，这两个参数是当前比较的两个元素。

返回值：大于0时将两个值互换，否则不换。

所以，我们就可以这样来写：

function sortNumber(a,b)
{
return a - b
}
var arr = new Array(6)
arr[0] = "10"
arr[1] = "5"
arr[2] = "40"
arr[3] = "25"
arr[4] = "1000"
arr[5] = "1"
document.write(arr + "<br />")
document.write(arr.sort(sortNumber))

当a - b > 0时，a和b交换，这个就是升序。

如果把 return a - b 写成 return b - a，这样就是降序。

有了这个基础之后，我们可以做多字段排序了。

先来一个两个字段的排序例子：

var jsonStudents = [
    {name:"Dawson", totalScore:"197", Chinese:"100",math:"97"},
    {name:"HanMeiMei", totalScore:"196",Chinese:"99", math:"97"},
    {name:"HanMeiMei", totalScore:"196",Chinese:"99", math:"10"},
    {name:"HanMeiMei", totalScore:"196",Chinese:"99", math:"80"},
    {name:"LiLei", totalScore:"185", Chinese:"88", math:"97"},
    {name:"XiaoMing", totalScore:"196", Chinese:"96",math:"100"},
    {name:"Jim", totalScore:"196", Chinese:"98",math:"98"},
    {name:"Joy", totalScore:"198", Chinese:"99",math:"99"}
];
jsonStudents.sort(function(a,b){
    if(a.totalScore === b.totalScore){
        return b.Chinese - a.Chinese;
    }
    return b.totalScore - a.totalScore;
});
console.log(jsonStudents);

再来一个三个字段的例子：

var jsonStudents = [
    {name:"Dawson", totalScore:"197", Chinese:"100",math:"97"},
    {name:"HanMeiMei", totalScore:"196",Chinese:"99", math:"97"},
    {name:"HanMeiMei", totalScore:"196",Chinese:"99", math:"10"},
    {name:"HanMeiMei", totalScore:"196",Chinese:"99", math:"80"},
    {name:"LiLei", totalScore:"185", Chinese:"88", math:"97"},
    {name:"XiaoMing", totalScore:"196", Chinese:"96",math:"100"},
    {name:"Jim", totalScore:"196", Chinese:"98",math:"98"},
    {name:"Joy", totalScore:"198", Chinese:"99",math:"99"}
];
jsonStudents.sort(function(a,b){
    if(a.totalScore === b.totalScore){
        if(b.Chinese === a.Chinese){
            return a.math - b.math;
        }
        return b.Chinese - a.Chinese;
    }
    return b.totalScore - a.totalScore;
});
console.log(jsonStudents);