🎯 挑一个数Pick a Number
从一列数里按位置或随机挑出一个。本地处理。可设置「方式」、「序号（从 1 起）」、「随机种子」。Pick one number from a list by index or at random. Processed locally. Settings: Mode, Index (from 1), Random seed.
使用说明与常见问题How-to & FAQ
「挑一个数」是什么？What is the Pick a Number tool?
从一列数里按位置或随机挑出一个。本地处理。可设置「方式」、「序号（从 1 起）」、「随机种子」。Pick one number from a list by index or at random. Processed locally. Settings: Mode, Index (from 1), Random seed.
如何使用「挑一个数」？How do I use the Pick a Number tool?
在「挑一个数」中，把内容粘贴或输入到上方输入框，按需设置「方式」、「序号（从 1 起）」、「随机种子」，结果会实时显示在下方，点击「复制结果」即可复制。In the Pick a Number: Paste or type into the input box, adjust "Mode", "Index (from 1)", "Random seed"; the result appears below instantly — click "Copy result" to copy it.
随机结果能复现吗？Can a random pick be repeated?
可以，填写随机种子后，同一列表和同一种子每次都抽到同一个数；留空则每次随机不同。按序号模式时，序号从 1 开始。Yes. With a random seed, the same list and seed always give the same pick; leave it blank for a fresh random choice each time. In index mode, positions start at 1.
列表怎么分成一项一项？How is the list split into items?
每行分开处理。一行里有逗号、分号或顿号时按它们分（所以“New York, Paris”是两项，名字里的空格会保留）；没有这些符号时按空格分。像 1,000 这样的千位分隔逗号不算分隔符。Each line is handled separately. If a line contains commas, semicolons or 、, it is split at those (so "New York, Paris" is two items and spaces inside a name are kept); otherwise it is split at spaces. A thousands comma such as 1,000 is not treated as a separator.
长数字会丢失精度吗？Do long numbers lose precision?
不会。每一项都按原文处理，挑出的项原样输出，不做任何数值计算，所以多长的数字都完整保留。No. Items are processed as text and the chosen item is returned exactly as typed, with no arithmetic, so long numbers are kept in full.
输入和输出是什么样的？What does the input and output look like?
例如在「挑一个数」中输入 10 20 30，「方式」设为 按序号，「序号（从 1 起）」设为 2，输出为：20。For example, the Pick a Number turns the input 10 20 30, "Mode" set to By index, "Index (from 1)" set to 2 into: 20.
有哪些选项可以调整？What options can I adjust?
「挑一个数」的设置：「方式」可选 按序号、随机（默认 按序号）；「序号（从 1 起）」默认 1；「随机种子」可留空。每次生成结果都按当前设置处理。Settings in the Pick a Number — "Mode": By index, Random (default By index); "Index (from 1)" default 1; "Random seed" optional. The result always uses the current settings.
「挑一个数」免费吗？需要注册吗？Is the Pick a Number free? Do I need an account?
「挑一个数」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 Pick a Number is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.