正则表达式范围在 0 到 100 之间，包括两位小数 [英] Regex range between 0 and 100 including two decimal

问题描述

我正在尝试找出执行以下操作的正则表达式.以下两个条件都必须为真:1) 0 到 100 之间(含)2) 可以只包含一位或两位小数但不是必须的.

I'm trying to figure out a regex expression that does the following. Both conditions below must be true: 1) Between 0 and 100 inclusive 2) Can contain one or two decimals only but not obligatory.

它不应该允许 100.01 或 100.1100 是最大值，或 100.0 或 100.00

It should not allow 100.01 or 100.1 100 is the maximum value, or 100.0 or 100.00

我试过 ^(100(?:\.00)?|0(?:\.\d\d)?|\d?\d(?:\.\d\d)?)$这帮助我解决了这个问题但这不接受 99.0 (一位小数).我可能非常接近.

I tried ^(100(?:\.00)?|0(?:\.\d\d)?|\d?\d(?:\.\d\d)?)$ which helped me in this question but this does not accept 99.0 (one decimal). I'm probably very close.

推荐答案

您只需要将每个第二个十进制数字设为可选:

You just need to make each second decimal digit optional:

^(?:100(?:\.00?)?|\d?\d(?:\.\d\d?)?)$
              ^                 ^

查看更新的正则表达式演示.0(?:\.\d\d)? 替代方案被 \d?\d(?:\.\d\d)? 一个(如根据 塞巴斯蒂安的评论)，因此可以删除.

See the updated regex demo. The 0(?:\.\d\d)? alternative is covered by \d?\d(?:\.\d\d)? one (as per Sebastian's comment) and can thus be removed.

? 量词匹配它所量化的子模式的一次或零次出现.

The ? quantifier matches one or zero occurrences of the subpattern it quantifies.

模式详情:

• ^ - 字符串的开始
• (?: - 交替组的开始:
  • 100(?:\.00?)? - 100、100.0 或 100.00(.00 是可选的，最后一个 0 也是可选的)
  • \d?\d(?:\.\d\d?)? - 一个可选数字，后跟一个强制性数字，后跟一个可选的点、数字和 一个可选的数字.
  • ^ - start of string
  • (?: - start of an alternation group:
    • 100(?:\.00?)? - 100, 100.0 or 100.00 (the .00 is optional and the last 0 is optional, too)
    • \d?\d(?:\.\d\d?)? - an optional digit followed by an obligatory digit followed with an optional sequence of a dot, a digit and an optional digit.

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