➕ CSV 末尾追加列Append Columns to CSV
在 CSV/TSV 表格的最右边追加一列或多列：填写新列名和填充值（可自动填入行号），自动识别分隔符，带引号和换行的单元格保持正确。Add one or more columns to the right end of a CSV or TSV table: give the new column names and a fill value (row numbers can be filled in). The delimiter is detected, and quoted cells with line breaks stay intact.
使用说明与常见问题How-to & FAQ
「CSV 末尾追加列」是什么？What is the Append Columns to CSV tool?
在 CSV/TSV 表格的最右边追加一列或多列：填写新列名和填充值（可自动填入行号），自动识别分隔符，带引号和换行的单元格保持正确。Add one or more columns to the right end of a CSV or TSV table: give the new column names and a fill value (row numbers can be filled in). The delimiter is detected, and quoted cells with line breaks stay intact.
如何使用「CSV 末尾追加列」？How do I use the Append Columns to CSV tool?
在「CSV 末尾追加列」中，把内容粘贴或输入到上方输入框，按需设置「新列名（逗号分隔）」、「填充值（{n} = 行号）」，结果会实时显示在下方，点击「复制结果」即可复制。In the Append Columns to CSV: Paste or type into the input box, adjust "New column names (comma separated)", "Fill value ({n} = row number)"; the result appears below instantly — click "Copy result" to copy it.
会改动原来的列吗？Does it change the existing columns?
不会。原有列的内容和顺序保持不变，新列追加在每一行的最后。要加在最前面请用“CSV 开头插入列”，要插在中间请用“CSV 插入列”。No. Existing columns keep their content and order; the new columns go at the end of every row. To add them at the front use Prepend Columns to CSV, and to put them in the middle use Insert Columns into CSV.
填充值里的 {n} 是什么？What does {n} in the fill value do?
{n} 会被替换成数据行的序号（表头不算，从 1 开始），比如填 ID-{n} 会得到 ID-1、ID-2……留空则新列是空单元格。所有新列使用同一个填充值。{n} is replaced with the data row number (the header doesn't count; it starts at 1), so ID-{n} gives ID-1, ID-2 and so on. Leave it blank for empty cells. Every new column gets the same fill value.
不勾选“第一行是表头”会怎样？What if 'First row is a header' is off?
那么每一行（包括第一行）都当作数据行，都会填入填充值；新列名只用来决定要加几列。Then every row, the first included, is a data row and gets the fill value; the new column names only decide how many columns are added.
含逗号或引号的单元格会被破坏吗？Will cells with commas or quotes break?
不会。输入按 CSV 规则解析（带引号的单元格里可以有逗号、引号和换行），输出时需要引号的单元格会重新加上引号，分隔符保持和输入一致。行长度不齐时先补齐空单元格，空行原样保留。No. The input is parsed by CSV rules (quoted cells may contain commas, quotes and line breaks), cells that need quotes get them again on output, and the delimiter stays the same as the input. Short rows are padded with empty cells first, and blank lines are kept.
代码或数据会被上传吗？Is my code or data uploaded?
不会。「CSV 末尾追加列」完全用 JavaScript 在本地运行，适合处理含有密钥、内部接口等敏感内容的数据。No. The Append Columns to CSV runs entirely in local JavaScript, so it is safe for data containing keys or internal endpoints.
「CSV 末尾追加列」免费吗？需要注册吗？Is the Append Columns to CSV free? Do I need an account?
「CSV 末尾追加列」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Append Columns to CSV is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.