陣列組和計數OCCURENCES

我有以下陣列：陣列組和計數OCCURENCES

var array = [ 
    { idOne: 1, oneText: 'one', idTwo: 2, twoText: 'two' }, 
    { idOne: 1, oneText: 'one', idTwo: 2, twoText: 'two' }, 
    { idOne: 12, oneText: 'twelve', idTwo: 23, twoText: 'twentythree' }, 
    { idOne: 12, oneText: 'twelve', idTwo: 23, twoText: 'twentythree' }, 
    { idOne: 12, oneText: 'twelve', idTwo: 25, twoText: 'twentyfive' }, 
    { idOne: 16, oneText: 'sixteen', idTwo: 56, twoText: 'fiftysix' }, 
    { idOne: 16, oneText: 'sixteen', idTwo: 56, twoText: 'fiftysix' }, 
    { idOne: 16, oneText: 'sixteen', idTwo: 56, twoText: 'fiftysix' }, 
    { idOne: 16, oneText: 'sixteen', idTwo: 50, twoText: 'fifty' }, 
    { idOne: 16, oneText: 'sixteen', idTwo: 50, twoText: 'fifty' }, 
    { idOne: 18, oneText: 'eighteen', idTwo: 90, twoText: 'ninety' } 
];

我想他們組首先吡咯烷酮，然後通過idTwo，並計算有多少人被發現，然後排序其中：

目前，我有以下方法：

var result = _.chain(array) 
    .groupBy("idOne") 
    .map(function(idOne, idOneKey) { 
     return _.chain(idOne) 
      .groupBy("idTwo") 
      .map(function(idTwo, idTwoKey) { 
       return {     
        id: idOneKey + '-' + idTwoKey 
       } 
      }) 
      .value(); 
    }) 
    .value();

但我想返回下面的數組或對象，不知道哪一個是最好的：

result = { 
    'one-two': 2, 
    'twelve-twentythree': 2, 
    'twelve-twentyfive': 1, 
    'sixteen-fiftysix': 3 
    ... 
}

它不必與下劃線或lodash，只要它工作。

來源

2017-10-19 fede_rosario

是本地JS的解決方案允許嗎？ – RomanPerekhrest

我正在實施這個反應的應用程序，所以無論真的工作... –

wouldnt你想要一個像這樣的結構的對象：{[idOne]：{[idTwo]：{object}}}？基本上是一個映射到對象的地圖？ – bryan60

你可以使用countBy而不是GROUPBY：

let result = _.countBy(array, item => item.oneText + '-' + item.twoText);

來源

2017-10-19 13:54:11

Ecamscript5替代解決方案（基於Array.reduce()功能）：

var arr = [ 
 
    { idOne: 1, oneText: 'one', idTwo: 2, twoText: 'two' }, { idOne: 1, oneText: 'one', idTwo: 2, twoText: 'two' }, 
 
    { idOne: 12, oneText: 'twelve', idTwo: 23, twoText: 'twentythree' }, { idOne: 12, oneText: 'twelve', idTwo: 23, twoText: 'twentythree' }, 
 
    { idOne: 12, oneText: 'twelve', idTwo: 25, twoText: 'twentyfive' }, { idOne: 16, oneText: 'sixteen', idTwo: 56, twoText: 'fiftysix' }, 
 
    { idOne: 16, oneText: 'sixteen', idTwo: 56, twoText: 'fiftysix' }, { idOne: 16, oneText: 'sixteen', idTwo: 56, twoText: 'fiftysix' }, 
 
    { idOne: 16, oneText: 'sixteen', idTwo: 50, twoText: 'fifty' }, { idOne: 16, oneText: 'sixteen', idTwo: 50, twoText: 'fifty' }, 
 
    { idOne: 18, oneText: 'eighteen', idTwo: 90, twoText: 'ninety' } 
 
], 
 
result = arr.reduce(function(r, o){ 
 
    var k = o.oneText +'-'+ o.twoText; 
 
    r[k] = (r[k])? (r[k]+1) : 1; 
 
    return r; 
 
}, {}); 
 

 
console.log(result);

來源

2017-10-19 13:46:48 RomanPerekhrest

你可以對哈希表來算使用的密鑰的陣列組。

var array = [{ idOne: 1, oneText: 'one', idTwo: 2, twoText: 'two' }, { idOne: 1, oneText: 'one', idTwo: 2, twoText: 'two' }, { idOne: 12, oneText: 'twelve', idTwo: 23, twoText: 'twentythree' }, { idOne: 12, oneText: 'twelve', idTwo: 23, twoText: 'twentythree' }, { idOne: 12, oneText: 'twelve', idTwo: 25, twoText: 'twentyfive' }, { idOne: 16, oneText: 'sixteen', idTwo: 56, twoText: 'fiftysix' }, { idOne: 16, oneText: 'sixteen', idTwo: 56, twoText: 'fiftysix' }, { idOne: 16, oneText: 'sixteen', idTwo: 56, twoText: 'fiftysix' }, { idOne: 16, oneText: 'sixteen', idTwo: 50, twoText: 'fifty' }, { idOne: 16, oneText: 'sixteen', idTwo: 50, twoText: 'fifty' }, { idOne: 18, oneText: 'eighteen', idTwo: 90, twoText: 'ninety' }], 
 
    result = {}; 
 

 
array.forEach(function (o) { 
 
    var key = ['oneText', 'twoText'].map(k => o[k]).join('-'); 
 
    result[key] = (result[key] || 0) + 1; 
 
}); 
 

 
console.log(result);

來源

2017-10-19 13:52:22

陣列組和計數OCCURENCES

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