有哪些方法实现数组去重1 let a = [1,1,1,3,5,6]const b = Array.from(new Set(a))2 const list = [] const arr = new Map()const c = a.forEach((item) => { if(!arr.has(item)){ arr.set(item,true) list.push(item) }})3 const list1 = []a.forEach((item) => {if(list1.indexOf(item) === -1) { list1.push(item)}})