如何通过jQuery/DOM操作编程修改表格单元格（如设置rowspan）

Absolutely you can! Once your table is rendered in the DOM, you have full control to manipulate its cells using jQuery or vanilla DOM methods—including merging cells via rowspan and removing the extra ones that get superseded. This is a totally valid approach, especially if you prefer building the base table first and then applying dynamic modifications.

Here's a step-by-step breakdown of how to pull this off:

1. Identify the target cells
   First, locate the column where you need to merge cells. For example, if you're targeting the 2nd column (zero-indexed as 1), you can select all its cells with $('table tr td:nth-child(2)').

2. Set the rowspan on the first cell in the range
   Pick the starting cell of your 24-row span and update its rowspan attribute to 24. Using jQuery, this would look like:

   // Select the first cell in the 24-row range (e.g., row 0 of the column)
   const firstCell = $('table tr td:nth-child(2)').eq(0);
   firstCell.attr('rowspan', 24);
   

3. Remove the excess cells
   You need to delete the next 23 cells in that column, since they're now covered by the merged cell. Use jQuery's slice() method to select those cells and remove them:

   // Select cells 1 to 23 (inclusive) in the column and remove them
   $('table tr td:nth-child(2)').slice(1, 24).remove();
   

Key Notes to Keep in Mind: #

• Table structure integrity: Make sure you're only removing cells that are fully contained within the column you're modifying—since your events don't cross columns, this shouldn't be an issue. Avoid removing cells that are part of other rows/columns that need to stay intact.
• Performance: For large tables (like your 60-row example), this operation is still lightweight, but if you're doing many such merges, consider batching the DOM updates (e.g., wrapping them in $(document).ready() or using requestAnimationFrame) to minimize layout thrashing.
• Debugging: If you run into issues, use your browser's dev tools to inspect the table before and after manipulation—this helps verify that the rowspan is set correctly and excess cells are removed.

And just to confirm: This approach works perfectly well even after the table is fully rendered. You don't have to build everything in a virtual array first if you prefer the "render then modify" workflow.

内容的提问来源于stack exchange，提问作者DaveC426913