30_eventloop.html 823 B

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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. <script>
  10. // promise 可以直接后边写 then和catch方法
  11. // new Promise((resolve,reject)=>{
  12. // resolve("3")
  13. // }).then((res)=>{
  14. // console.log(res);
  15. // }).catch((err)=>{
  16. // console.log(err);
  17. // })
  18. console.log("1");
  19. setTimeout(() => {
  20. console.log("2");
  21. }, 0);
  22. new Promise((resolve, reject) => {
  23. // setTimeout(() => {
  24. resolve("3")
  25. // }, 0);
  26. }).then((res) => {
  27. console.log(res);
  28. })
  29. console.log("4");
  30. </script>
  31. </body>
  32. </html>