1.数组遍历

  1. var arr = ['red','green','blue'];
  2. for (var i=0;i<arr.length;i++){
  3.      console.log(arr[i]);
  4. }

2.对象遍历

  1. //第一种
  2. const obj = {
  3.   id: 1,
  4.   name: "zhangsan",
  5.   age: 18,
  6. };
  8. for (let key in obj) {
  9.   console.log(key + "---" + obj[key]);
  10. }
  11. //第二种
  12. const obj1 = {
  13.   id: 1,
  14.   name: "zhangsan",
  15.   age: 18,
  16. };
  18. console.log(Object.keys(obj1));
  20. console.log(Object.values(obj1));
  21. //第三种
  22. const obj2 = {
  23.   id: 1,
  24.   name: "zhangsan",
  25.   age: 18,
  26. };
  27. Object.getOwnPropertyNames(obj2).forEach(function (key) {
  28.   console.log(key + "---" + obj2[key]);
  29. });