Examples and comparison of 3 methods for deduplication of JS object arrays

1. Comparison of data before and after deduplication

// The original data is like this // The data after deduplication is like this [{ [{
  "goodsId": "1", "goodsId": "1",
  "quota": 12, "quota": 12,
  "skuId": "1"
}, },
{ {
  "goodsId": "2", "goodsId": "2",
  "quota": 12, "quota": 12,
  "skuId": "2"
}, }]
{
  "goodsId": "1",
  "quota": 12,
  "skuId": "1"
}]

2. How to use

1. Using filter and Map 🌟🌟🌟🌟🌟
2. Using reduce 🌟🌟🌟🌟
3. for loop 🌟🌟🌟

Conclusion: The time difference between filter and reduce is not too big. Filter is slightly faster, but the filter syntax is more concise.

1. Use filter and Map

The code is concise and easy to use. It can be done in 4 lines of code. The average time spent is the shortest. Five-star recommendation

function uniqueFunc(arr, uniId){
  const res = new Map();
  return arr.filter((item) => !res.has(item[uniId]) && res.set(item[uniId], 1));
}

2. Use reduce

A little more code, average time spent is on par with the first one, four-star recommendation

function uniqueFunc2(arr, uniId){
  let hash = {}
  return arr.reduce((accum,item) => {
    hash[item[uniId]] ? '' : hash[item[uniId]] = true && accum.push(item)
    return accum
  },[])
}

3. Using for loop

It takes a little more time than the first and second ones, but the time spent is average, Samsung recommends

function uniqueFunc3(arr, uniId){
  let obj = {}
  let tempArr = []
  for(var i = 0; i<arr.length; i++){
    if(!obj[arr[i][uniId]]){
      tempArr.push(arr[i])
      obj[arr[i][uniId]] = true
    }
  }
  return tempArr
}

3. Comparison of processing time of three methods for 2400 data

Test time screenshot display

Summarize

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