不使用 For 循环处理任何数组

Question

我想在不使用FOR循环的情况下动态实现输出。输入是多个对象的数组。

var input = [

  {

    "name": "Siner1",

    "RTime": 40,

    "FTime": 30

  },

  {

    "name": "Siner2",

    "RTime": 50,

    "FTime": 60

  }

]

var output = [

  {

    "RTime": {

      "Siner1": 40,

      "Siner2": 50

    },

    "FTime": {

      "Siner1": 30,

      "Siner2": 60

    }

  }

]

//console.log(input)

console.log(output);

有人可以帮助我吗？

Answer 1

方法一var input = [  {    "name": "Siner1",    "RTime": 40,    "FTime": 30  },  {    "name": "Siner2",    "RTime": 50,    "FTime": 60  }]var output = input.reduce(function(initial,next){   initial["RTime"][next["name"]]=(initial["RTime"][next["name"]] || 0 ) + next["RTime"];   initial["FTime"][next["name"]]=(initial["FTime"][next["name"]] || 0 ) + next["FTime"];   return initial;},{"RTime":{},"FTime":{}});console.log(output)方法二如果您想要聚合其他键或值var input = [  {    "name": "Siner1",    "RTime": 40,    "FTime": 30  },  {    "name": "Siner2",    "RTime": 50,    "FTime": 60  }]var keys = ['RTime','FTime'];output=input.reduce(function(initial,next){   keys.map(function(key){        initial[key][next["name"]]=(initial[key][next["name"]] || 0 ) + next[key];   });   return initial;},keys.reduce(function(data,key){   data[key]={};   return data;},{}));console.log(output)

Answer 2

提供的通用方法基于Array.prototype.reduce. 由于它使用accumulator其回调函数的参数作为可配置项，collector因此它完全不知道任何给定列表的任何已处理项目的键。只需要提供已处理项目的（源）键值，然后作为新分组键值的目标键...function restructureKeysAndValues(collector, item) {  const {    keyOfTargetValue,    registry,    index,    list  } = collector;  const targetKey = item[keyOfTargetValue];  Object.entries(item).forEach(([key, value]) => {    if (key !== keyOfTargetValue) {      let keyGroup = registry[key];      if (!keyGroup) {        keyGroup = registry[key] = { [key]: {} };        Object.assign(index, keyGroup);        list.push(keyGroup);      }      keyGroup[key][targetKey] = value;    }  });  return collector;}console.log('a list of group objects ...', [{    "name": "Siner1",    "RTime": 40,    "FTime": 30  }, {    "name": "Siner2",    "RTime": 50,    "FTime": 60  }].reduce(restructureKeysAndValues, {    keyOfTargetValue: 'name',    registry: {}, // - for internal tracking    index: {},    // - for external use, output as map/index.     list: []      // - for external use, output as array/list.  }).list);console.log('a single grouped object ...', [{    "name": "Siner1",    "RTime": 40,    "FTime": 30  }, {    "name": "Siner2",    "RTime": 50,    "FTime": 60  }].reduce(restructureKeysAndValues, {    keyOfTargetValue: 'name',    registry: {}, // - for internal tracking    index: {},    // - for external use, output as map/index.     list: []      // - for external use, output as array/list.  }).index);console.log('a list of group objects ...', [{    "name": "Siner1",    "RTime": 40,    "FTime": 30,    "CTime": 70,    "ATime": 90  }, {    "name": "Siner2",    "RTime": 50,    "FTime": 60,    "CTime": 30,    "ATime": 40  }, {    "name": "Siner3",    "RTime": 90,    "FTime": 20,    "CTime": 10,    "ATime": 20  }].reduce(restructureKeysAndValues, {    keyOfTargetValue: 'name',    registry: {}, // - for internal tracking    index: {},    // - for external use, output as map/index.     list: []      // - for external use, output as array/list.  }).list);.as-console-wrapper { min-height: 100%!important; top: 0; }