JS 数组去重

Set 方式去重

let array = [1, 2, 3, 4, 5, 6, 6, 7]
console.log(array)
let unique = (array) => [...new Set(array)]
console.log(unique(array))

Map 方式去重

let arr = [1, 2, 3, 3, 4, 5, 2, 5]
console.log(arr)
let uniqueVal = uniqueArr(arr)
console.log(uniqueVal)

function uniqueArr (arr) {
  const seen = new Map()
  return arr.filter((arr) => !seen.has(arr) && seen.set(arr, 1))
}

键值对 方式去重

let arr = [1, 2, 3, 3, 4, 5, 2, 5]
function uniqueArray (arr) {
  let obj = {}
  return arr.filter((item, index, arr) => {
    return obj.hasOwnProperty(typeof item + item) ? false : (obj[typeof item + item] = true)
  })
}

console.log(uniqueArray(arr))

去重引用类型

let arrObj = [{'id': 1, 'name': 'abc'}, {'id': 1, 'name': 'abc'}, {'id': 2, 'name': 'bcd'}, {'id': 3, 'name': 'efg'}]
console.log('arrObj: ', arrObj)

let hash = {}
arrObj = arrObj.reduce((item, next) => {
  hash[next.name] ? '' : hash[next.name] = true && item.push(next)
  return item
}, [])

console.log(arrObj)