5.类数组.html 1013 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. <ul>
  10. <li>你好</li>
  11. <li>你好</li>
  12. <li>你好</li>
  13. <li>你好</li>
  14. </ul>
  15. <script>
  16. // 类数组 具备length 索引 但是不具备真是数组的方法
  17. // NodeList arguments
  18. function fn1() {
  19. console.log(arguments,'arguments')
  20. console.log(arguments[1],'arguments')
  21. console.log(arguments instanceof Array,'arguments instanceof Array')
  22. }
  23. fn1('a','b')
  24. // 类数组转换数组
  25. let arr1 = {0:1,1:2,2:3,length:3};
  26. console.log(arr1,'arr1');
  27. console.log(Array.from(arr1))
  28. let x = document.querySelectorAll('li');
  29. // console.log([...x])
  30. console.log(Array.prototype.slice.call(arr1));
  31. console.log(Array.apply(null,arr1));
  32. </script>
  33. </body>
  34. </html>