排序数组多维javascript答案

【问题标题】：sort array multidimensional javascript排序数组多维javascript
【发布时间】：2017-10-10 18:10:50
【问题描述】：

我必须对此进行排序：我从两个不同的select 查询中获取数据库中的数据，我必须按mpriority 和mdate 对它们进行排序。

我知道如何对对象数组进行排序，但我不能使用 object 或 object.key

    var allocations = new Array(); 
    allocations[0] =
    [   qtA =  15,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp=  11,
        mpriority=  5,
        mdate=  new Date('2017-04-27 11:26:02.147'),
    ];

allocations[1] =
    [
        qtA= 13,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp= 11,
        mpriority= 5,
        mdate= new Date('2016-10-07 00:00:00.000'),
    ];

allocations[2] =
    [
        qtA= 16,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp= 11,
        mpriority= 4,
        mdate= new Date('2017-04-27 11:26:02.147'),
    ];

allocations[3] =
    [
        qtA= 95,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp= 11,
        mpriority= 1,
        mdate= new Date('2016-10-06 00:00:00.000'),
    ];

allocations[4] =
    [
        qtA= 75,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp= 11,
        mpriority= 8,
        mdate= new Date('2017-02-20 12:41:34.903'),
    ];

allocations[5] =
    [
        qtA= 45,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp= 11,
        mpriority= 0,
        mdate= new Date('2017-04-27 11:26:02.147'),
    ];

排序函数应该首先查看mpriority - 如果两个值相同，则检查mdate

我觉得应该是这样的

var sortOptions = {
    byPriorityAndDate: function (a, b) {
        return (b.mpriority - a.mpriority) || (a.mdate - b.mdate);
    },
}

以及如何检查我正在处理的 js 版本？

【问题讨论】：

您的排序功能遇到了什么问题？注意：（1）您的数组定义的语法没有按照您的想法执行。 (2) 要了解 JavaScript 的版本，请阅读浏览器的版本发布内容。另见this simple check
这是伪代码还是什么？因为看起来你正在尝试创建一个对象而不是一个数组

标签： javascript arrays sorting multidimensional-array

【解决方案1】：

你有数组数组，而不是对象数组。

我建议您将数组数组转换为对象数组，像这样实例化每个元素：

allocations[0] = {
    qtA:  15,
    mdata:  '1234',
    mid:  '234234234',
    qtyToDoTemp:  11,
    mpriority:  5,
    mdate:  new Date('2017-04-27 11:26:02.147'),
};

这样你编写的比较函数应该可以工作

另外，我建议您阅读Compare two dates with JavaScript 以了解您想要哪种比较

无论如何，这种排序功能适用于您的情况：

allocations = allocations.sort((a, b) => {
   if (a[4] === b[4]) {
        return a[5].getTime() - b[5].getTime();
   }

   return a[4] - b[4];
})

var allocations = new Array(); 
    allocations[0] =
    [   qtA =  15,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp=  11,
        mpriority=  5,
        mdate=  new Date('2017-04-27 11:26:02.147'),
    ];

allocations[1] =
    [
        qtA= 13,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp= 11,
        mpriority= 5,
        mdate= new Date('2016-10-07 00:00:00.000'),
    ];

allocations[2] =
    [
        qtA= 16,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp= 11,
        mpriority= 4,
        mdate= new Date('2017-04-27 11:26:02.147'),
    ];

allocations[3] =
    [
        qtA= 95,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp= 11,
        mpriority= 1,
        mdate= new Date('2016-10-06 00:00:00.000'),
    ];

allocations[4] =
    [
        qtA= 75,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp= 11,
        mpriority= 8,
        mdate= new Date('2017-02-20 12:41:34.903'),
    ];

allocations[5] =
    [
        qtA= 45,
        mdata=  '1234',
        mid =  '234234234',
        qtyToDoTemp= 11,
        mpriority= 0,
        mdate= new Date('2017-04-27 11:26:02.147'),
    ];

allocations = allocations.sort((a, b) => {
   if (a[4] === b[4]) {
        return a[5].getTime() - b[5].getTime();
   }
   
   return a[4] - b[4];
})

console.log(allocations)

【讨论】：

【解决方案2】：

好的，在这里我已经重写了你的代码，以便它执行我认为你希望它执行的操作：

var allocations = []; 
allocations.push({
  qtA: 15,
  mdata: '1234',
  mid: '234234234',
  qtyToDoTemp: 11,
  mpriority: 5,
  mdate: new Date('2017-04-27 11:26:02.147')
});

allocations.push({
  qtA: 13,
  mdata: '1234',
  mid: '234234234',
  qtyToDoTemp: 11,
  mpriority: 5,
  mdate: new Date('2016-10-07 00:00:00.000')
});

allocations.push({
  qtA: 16,
  mdata: '1234',
  mid: '234234234',
  qtyToDoTemp: 11,
  mpriority: 4,
  mdate: new Date('2017-04-27 11:26:02.147')
});

allocations.push({
  qtA: 95,
  mdata: '1234',
  mid: '234234234',
  qtyToDoTemp: 11,
  mpriority: 1,
  mdate: new Date('2016-10-06 00:00:00.000')
});

allocations.push({
  qtA: 75,
  mdata: '1234',
  mid: '234234234',
  qtyToDoTemp: 11,
  mpriority: 8,
  mdate: new Date('2017-02-20 12:41:34.903')
});

allocations.push({
  qtA: 45,
  mdata: '1234',
  mid: '234234234',
  qtyToDoTemp: 11,
  mpriority: 0,
  mdate: new Date('2017-04-27 11:26:02.147')
});

如果您不熟悉 Javascript 并且来自不同的语言，请了解这一点：JS 中的数组与其他语言中的数组不同，它们是具有特殊语法的对象，并且尽力表现得像数组。

【讨论】：

【解决方案3】：

您初始化数组的方式是错误的。尽管它运行时不会出错，但它的作用与您的预期不同。

这个：

allocations[0] =
[   qtA =  15,
    mdata=  '1234',
    mid =  '234234234',
    qtyToDoTemp=  11,
    mpriority=  5,
    mdate=  new Date('2017-04-27 11:26:02.147'),
];

...实际上会将值分配给全局变量，如下所示：

qtA =  15,
mdata=  '1234',
mid =  '234234234',
qtyToDoTemp=  11,
mpriority=  5,
mdate=  new Date('2017-04-27 11:26:02.147')

然后数组将在索引 0 处获得一个嵌套数组，其中包含以下值：

allocations[0] = [
    15,
    '1234',
    '234234234',
    11,
    5,
    new Date('2017-04-27 11:26:02.147'),
];

因此，您的代码的结果是嵌套数组的数组，而不是对象的数组。

要创建对象数组，请使用以下语法：

var allocations = [{
    qtA: 15,
    mdata:  '1234',
    mid:  '234234234',
    qtyToDoTemp:  11,
    mpriority:  5,
    mdate:  new Date('2017-04-27 11:26:02.147'),
}, {
    qtA: 13,
    mdata:  '1234',
    mid :  '234234234',
    qtyToDoTemp: 11,
    mpriority: 5,
    mdate: new Date('2016-10-07 00:00:00.000'),
}, {
    // ...etc, etc
}];

现在你的函数可以工作了：

var sortOptions = {
    byPriorityAndDate: function (a, b) {
        return (b.mpriority - a.mpriority) || (a.mdate - b.mdate);
    },
}

var allocations = [{
    qtA: 15,
    mdata:  '1234',
    mid:  '234234234',
    qtyToDoTemp:  11,
    mpriority:  5,
    mdate:  new Date('2017-04-27 11:26:02.147'),
}, {
    qtA: 13,
    mdata:  '1234',
    mid :  '234234234',
    qtyToDoTemp: 11,
    mpriority: 5,
    mdate: new Date('2016-10-07 00:00:00.000'),
}, {
    qtA: 16,
    mdata:  '1234',
    mid :  '234234234',
    qtyToDoTemp: 11,
    mpriority: 4,
    mdate: new Date('2017-04-27 11:26:02.147'),
}, {
    qtA: 95,
    mdata:  '1234',
    mid :  '234234234',
    qtyToDoTemp: 11,
    mpriority: 1,
    mdate: new Date('2016-10-06 00:00:00.000'),
}, {
    qtA: 75,
    mdata:  '1234',
    mid :  '234234234',
    qtyToDoTemp: 11,
    mpriority: 8,
    mdate: new Date('2017-02-20 12:41:34.903'),
}, {
    qtA: 45,
    mdata:  '1234',
    mid:  '234234234',
    qtyToDoTemp: 11,
    mpriority: 0,
    mdate: new Date('2017-04-27 11:26:02.147'),
}];

allocations.sort(sortOptions.byPriorityAndDate);

console.log(allocations);

.as-console-wrapper { max-height: 100% !important; top: 0; }

【讨论】：