JavaScript過濾器回圈不回圈遍歷陣列中的所有專案

在下面的代碼中，我試圖過濾資料。但是，我在演算法中看到它回圈遍歷userPassedFilter陣列中的第一項并回傳過濾后的資料，但不會再次回圈以檢查userPassedFilter陣列中的第二項。我知道這是因為我在遍歷整個userPassedFilter陣列之前呼叫 return true 。我如何確保在演算法中它userPassedFilter在回傳最終結果之前回圈遍歷所有專案？

**User Selected Filter**
let userPassedFilter = [{"phase":1},{"phase":2}]

**Data**
let dataList = [
{"voltage":35, "phase":2},
{"voltage":12, "phase":2},
{"voltage":12, "phase":3},
{"voltage":35, "phase":1}
]

**Filter Data Algorithm** 
module.exports = {

  filterData: (dataList, userPassedFilter)=>{
    let filteredData = [];

    filteredData = dataList.filter((data) =>{
    for(let item of userPassedFilter){
        for(let key in item){
          if(data[key] === undefined || data[key] !== item[key])
          return false
        }
        


      }
return true
    })

return filteredData

}
}

uj5u.com熱心網友回復：

filter在dataList與回傳，每一個物件some的物件屬性都包含在userFilter。

const userPassedFilter = [{voltage:122},{phase:1},{phase:2},{voltage:44}];

const dataList = [
  {voltage:44, phase:12},    
  {voltage:35, phase:2},
  {voltage:12, phase:2},
  {voltage:12, phase:3},
  {voltage:35, phase:1},
  {voltage:122, phase:156}
];

function filterData(dataList, userPassedFilter) {
  return dataList.filter(obj => {
    return userPassedFilter.some(inner => {
      const [[ key, value ]] = Object.entries(inner);
      return obj[key] === value;
    });
  });
}

console.log(filterData(dataList, userPassedFilter));

uj5u.com熱心網友回復：

為每個回圈引入變數，因此結果將userPassedFilter通過匹配元素的所有屬性來匹配 中的任何元素。

let userPassedFilter = [{"phase":1},{"phase":2}];
let dataList = [{"voltage":35, "phase":2},{"voltage":12, "phase":2},{"voltage":12, "phase":3},{"voltage":35, "phase":1}];

const f = (dataList, userPassedFilter) => {
  let filteredData = dataList.filter((data) => {
    let filtered = true;
    for (let item of userPassedFilter) {
      let matched = true;
      for (let key in item) {
        if (data[key] === undefined || data[key] !== item[key]) {
          matched = false;
          break;
        }
      }
      if (matched) {
        filtered = false;
        break;
      }
    }
    return !filtered;
  });
  return filteredData;
};

console.log(f(dataList, userPassedFilter));

更短的版本：

let userPassedFilter = [{"phase":1},{"phase":2}];
let dataList = [{"voltage":35, "phase":2},{"voltage":12, "phase":2},{"voltage":12, "phase":3},{"voltage":35, "phase":1}];

const f = (dataList, userPassedFilter) => {
  let filteredData = dataList.filter((data) => {
    return userPassedFilter.some(item => Object.entries(item).every(([key, value]) => data[key] === value))
  });
  return filteredData;
};

console.log(f(dataList, userPassedFilter));

uj5u.com熱心網友回復：

嘗試添加一個變數

filteredData = dataList.filter((data) => {
   let myvar = true;
   for(let item of userPassedFilter){
      for(let key in item){
         if(data[key] === undefined || data[key] !== item[key])
          myvar = false
      }
   }
   return myvar
})

uj5u.com熱心網友回復：

嘗試添加一個變數來保存值：

let userPassedFilter = [{
  "phase": 1
}, {
  "phase": 2
}]

let dataList = [{
    "voltage": 35,
    "phase": 2
  },
  {
    "voltage": 12,
    "phase": 2
  },
  {
    "voltage": 12,
    "phase": 3
  },
  {
    "voltage": 35,
    "phase": 1
  }
]


function filterData(dataList, userPassedFilter) {
  let filteredData = [];

  filteredData = dataList.filter((data) => {
    var throwVar = 0 //add this variable to hold the value
    for (let item of userPassedFilter) {
      for (let key in item) {
        if (data[key] === undefined || data[key] !== item[key]) {
          throwVar = 0
        } else {
          return true
        }
      }



    }
    if (throwVar == 0) {
      return false
    }
  })

  return filteredData

}


console.log(filterData(dataList, userPassedFilter))

標籤：javascript

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