17.map.html 1.1 KB

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  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <meta charset="UTF-8">
  5. <meta name="viewport" content="width=device-width, initial-scale=1.0">
  6. <title>Document</title>
  7. </head>
  8. <body>
  9. <!--
  10. map 类似于对象 键值对中的对象
  11. set() 设置集合中的键值对
  12. get() 获取集合中键值对属性值
  13. has() 查找集合中的属性是否存在
  14. clear() 清空集合
  15. -->
  16. <script>
  17. let m1 = new Map();
  18. console.log(m1);
  19. let m2 = new Map([
  20. ["name","Tom"],
  21. ["age","10"]
  22. ])
  23. console.log(m2);
  24. m2.set("sex","男")
  25. console.log(m2.get("name"));
  26. console.log(m2.has("age1"));
  27. // m2.clear()
  28. console.log(m2);
  29. let list = [34,45,56,67,78];
  30. list.map((ele,index)=>{
  31. console.log(ele,'a',index)
  32. })
  33. for(let k of m2.keys()) {
  34. console.log(k)
  35. }
  36. for(let k of m2.values()) {
  37. console.log(k)
  38. }
  39. for(let k of m2.entries()) {
  40. console.log(k)
  41. }
  42. </script>
  43. </body>
  44. </html>