如何编写匹配10-50间可选带-1/2数值的正则表达式？

云上老周

2026-5-27

Regex for Validating 10-50 (Inclusive) with Optional "-1/2" Suffix

Alright, let's build exactly what you need for your text box validation. First, let's lock in the requirements to make sure we cover every case: we need to match integers from 10 up to 50 (including 50), and allow an optional "-1/2" suffix—so both pure integers like 50 and values like 49-1/2 should pass without issue.

Final Regex

^(1[0-9]|[2-4][0-9]|50)(-1/2)?$

Let's Break It Down

Every part of this regex serves a specific purpose, so you know exactly why it works:

^ and $: These anchors ensure we match the entire input string—no extra spaces, leading/trailing characters, or partial matches slip through. Critical for text box validation where you don't want invalid input sneaking in!
1[0-9]: Catches all numbers from 10 to 19 (starts with a 1, followed by any digit 0-9)
[2-4][0-9]: Covers every integer from 20 to 49 (starts with 2, 3, or 4, followed by any digit 0-9)
50: Explicitly matches the upper limit (since 50 doesn't fit the previous patterns, we call it out directly to avoid gaps)
(-1/2)?: The ? makes this group optional—so the "-1/2" suffix can appear 0 or 1 times. Perfect for allowing both pure integers and the suffixed version you need.