在日期属性中按天按数组重新组合答案

【问题标题】：Regroup by array by day in date property在日期属性中按天按数组重新组合
【发布时间】：2017-08-07 00:22:13
【问题描述】：

如何在日期属性中创建一个按天重新组合数组的函数

例如我有这个数组..

var _array = [ 
{name:"sample1" ,date:'08-07-2017'}, 
{name:"sample2" ,date:'08-07-2017'},
{name:"sample3" ,date:'08-08-2017'},
{name:"sample4" ,date:'08-09-2017'},
{name:"sample5" ,date:'08-09-2017'},
{name:"sample5" ,date:'08-09-2017'},
];

然后我调用函数 regroup

regroup_byday(_array);

预期输出是

{ 
   [
    {name:"sample1" ,date:'08-07-2017'}, 
    {name:"sample2" ,date:'08-07-2017'},
   ],

   [
   {name:"sample3" ,date:'08-08-2017'}, 
   ],

   [
    {name:"sample4" ,date:'08-09-2017'},
    {name:"sample5" ,date:'08-09-2017'},
    {name:"sample5" ,date:'08-09-2017'},
   ]
};

提前致谢！ ..

【问题讨论】：

标签： javascript jquery arrays momentjs

【解决方案1】：

以下应该会产生您正在寻找的所需输出：

var _array = [
{name:"sample1" ,date:'08-07-2017'}, 
{name:"sample2" ,date:'08-07-2017'},
{name:"sample3" ,date:'08-08-2017'},
{name:"sample4" ,date:'08-09-2017'},
{name:"sample5" ,date:'08-09-2017'},
{name:"sample5" ,date:'08-09-2017'}
];

var regrouped = [];

for (var i = 0; i < _array.length; i++) {
  var addNew = true;
  for (var j = 0; j < regrouped.length; j++) {
    if (_array[i].date === regrouped[j][0].date) {
      regrouped[j].push(_array[i]);
      addNew = false;
    }
  }
  if (addNew) {
    regrouped.push([_array[i]]);
  }
}

console.log(regrouped);

【讨论】：

【解决方案2】：

遍历数组并将结果推送到以日期为键的中间Object，Object的值就是你所需要的：

var _array = [ 
{name:"sample1" ,date:'08-07-2017'}, 
{name:"sample2" ,date:'08-07-2017'},
{name:"sample3" ,date:'08-08-2017'},
{name:"sample4" ,date:'08-09-2017'},
{name:"sample5" ,date:'08-09-2017'},
{name:"sample5" ,date:'08-09-2017'},
];

var result = Object.values(
  _array.reduce((regroup, obj) => {
    if(regroup[obj.date] === undefined) {
      regroup[obj.date] = [obj];
    } else {
      regroup[obj.date].push(obj);
    }
    return regroup;
  }, {})
);

console.log(result);

【讨论】：