ES6数组去重

const arr = [1, 2, 3, 1, 2, 4, 5]

// 方法一
const uniqueSet = new Set(arr)
const unique01 = [...uniqueSet]
const unique = Array.from(uniqueSet)

// 方法二
const unique02 = arr.filter((item,index) => { 
  return arr.indexOf(item)===index
})

// 方法三
const unique03 = arr.reduce((accumulator, currentValue) => {
  accumulator.includes(currentValue) ? accumulator : [...accumulator, currentValue]
}, [])

参考链接：How to Remove Array Duplicates in ES6