数组排序

冒泡排序

var arr = [2, 1, 4, 6, 6, 7, 9, 3]
for (let i = 0; i < arr.length; i++) {
  for (let j = 0; j < arr.length; j++) {
    if (arr[j] > arr[j + 1]) {
      var keep = arr[j]
      arr[j] = arr[j + 1]
      arr[j + 1] = keep
    }
  }
}

es6排序

var arr = [2, 1, 4, 6, 6, 7, 9, 3]
arr.sort((a, b) => a - b)

数组去重

原生去重

var arr = [2, 3, 4, 6, 6, 7, 9, 3, 2, 4, 6]
const unique = arr => {
  const uniqueArr = []
  for (let i = 0; i < arr.length; i++) {
    if (uniqueArr.indexOf(arr[i]) === -1) {
      uniqueArr.push(arr[i])
    }
  }
  return uniqueArr
}
console.log(unique(arr))

es6去重

var arr = [2, 3, 4, 6, 6, 7, 9, 3, 2, 4, 6]
var uniqueArr1 = [...new Set(arr)]
var uniqueArr2 = Array.from(new Set(arr))