如何编写匹配50%至150%数值的Regex正则表达式？

Got it, let's figure out how to write a regex that catches percentages between 50% and 150% (including both endpoints). I'll break this down step by step, covering whole numbers first, then extending to decimals if you need that.

Matching Whole Number Percentages #

We can split the range into three distinct parts to cover every valid whole number case:

• 50% to 99%: Two-digit numbers from 50 up to 99, followed by a % sign → [5-9][0-9]%
• 100% to 149%: Three-digit numbers starting with 1, tens digit from 0-4, any units digit → 1[0-4][0-9]%
• 150%: The exact upper limit, since it's a unique value → 150%

Combine these with the | (OR) operator, wrap them in a non-capturing group, and add word boundaries to avoid partial matches (like picking up 50% from 1500%):

\b(?:[5-9][0-9]%|1[0-4][0-9]%|150%)\b

• \b = Word boundary: Ensures we don't match partial numbers embedded in longer strings.
• (?:...) = Non-capturing group: Groups the patterns together without creating an unnecessary capture group.

Matching Percentages with Decimals #

If you need to support values like 50.5% or 149.99%, we can adjust the regex to allow optional decimal parts. Here are two common scenarios:

Allow Any Number of Decimal Places #

This works for values like 50.1%, 123.456%, and 150.0% (but blocks 150.1% since it's over the limit):

\b(?:[5-9][0-9](?:\.\d+)?%|1[0-4][0-9](?:\.\d+)?%|150(?:\.0+)?%)\b

• (?:\.\d+)? = Optional decimal point followed by one or more digits.
• For 150%, we use (?:\.0+)? to only allow trailing zeros (so 150.0% is okay, but 150.1% isn't).

Limit to 1-2 Decimal Places #

If you want to restrict decimals to a reasonable number (like currency-style precision):

\b(?:[5-9][0-9](?:\.\d{1,2})?%|1[0-4][0-9](?:\.\d{1,2})?%|150(?:\.0{1,2})?%)\b

• \d{1,2} = Matches 1 or 2 digits after the decimal point.

Quick Test Cases #

• ✅ Matches: 50%, 75%, 100%, 149%, 150%, 50.5%, 149.99%, 150.0%
• ❌ Doesn't match: 49%, 151%, 200%, 500%, 150.1%

内容的提问来源于stack exchange，提问作者Djones12