sort函數實現多條件排序

js的sort方法，我們一般傳入一個回調用於單排序，也就根據某一個條件排序，那么一個場景需要多條件排序(多重排序)，我們怎么處理呢？

如下例子，我們按學生的總分排序，如果總分相等，我們再按照語文成績排序。

var jsonStudents = [
    { name: "Dawson", totalScore: "197", Chinese: "100", math: "97" },
    { name: "HanMeiMei", totalScore: "196", Chinese: "99", math: "97" },
    { 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) {
    var value1 = a.totalScore,
        value2 = b.totalScore;
    //總分相同 
    if (value1 === value2) {
        // 按語文分數降序排序
        return b.Chinese - a.Chinese;
    }
    // 總分不同，降序排序
    return value2 - value1;
});

console.log("jsonStudents :", jsonStudents);

關鍵點在於sort回調如何定義排序規則