// 查找一个数组中，出现次数前三的字符 let arr = [1, 1, 1, 3, 3, 3, 5, 5, 2, 3, 6] function findNum(arr) { let map = new Map() for (let i = 0; i < arr.length; i++) { if (!map.has(arr[i])) { map.set(arr[i], 1) } else { map.set(arr[i], 1 + map.get(arr[i])) } } let res = Array.from(map).sort((a, b) => { return b[1] - a[1] }) console.log(res[0][0], res[1][0], res[2][0]); } findNum(arr)