[JavaScript] 数组去重

1、假如数组元素不是对象，如

let arr = [1, 2, 3, 2, 'a', 'b', 'a']
let set = new Set(data)
let newArr = [...set] // 数组去重
console.log(newArr)

2、假如数组元素是对象，如

// 数组中的对象 去掉value相同的对象
let arr = [{value: 1, time:111,}, {value: 2, time: 222}, {value: 3, time: 333},  {value: 2, time: 222}]
let newArr = arr.reduce((pre, cur) => {
　　// console.log('pre', pre, 'cur', cur)
　　let index = pre.findIndex((item) => {
   　　return item.value === cur.value
   })
   index === -1 && pre.push(cur)
   return pre
}, [])

console.log(newArr)