求验证ClassName.PropertyName格式的正确Regex正则表达式

Got it, let's sort out this regex problem for you! The issue with your original ^\w+(\.\w+)*$ is that \w includes digits and underscores, and it doesn't restrict the first character to be a letter—exactly why those invalid entries like 2Personnel.FirstName1 or Personnel.33FirstName were slipping through.

The Correct Regex #

Here's a regex that enforces the proper naming convention (class/property names start with a letter, followed by letters, digits, or underscores):

^[A-Za-z][A-Za-z0-9_]*(\.[A-Za-z][A-Za-z0-9_]*)*$

Let's Break It Down #

• ^: Anchors the match to the start of the string
• [A-Za-z]: Ensures the first character is an uppercase or lowercase letter (no digits/underscores allowed here)
• [A-Za-z0-9_]*: Allows any number of letters, digits, or underscores after the first character (the * means 0 or more)
• (\.[A-Za-z][A-Za-z0-9_]*)*: Handles optional nested property names—each segment after a dot must follow the same "letter-first" rule, and you can have zero or more of these segments
• $: Anchors the match to the end of the string (prevents extra, invalid characters from being added)

Test Cases #

• Valid matches:
  • Personnel.FirstName ✅
  • UserProfile.EmailAddress ✅
  • OrderDetails.ShippingInfo.ZipCode ✅
• Invalid matches that will be rejected:
  • 2Personnel.FirstName1 ❌ (starts with a digit)
  • Personnel.33FirstName ❌ (property name starts with a digit)
  • Personnel.First-Name ❌ (contains an invalid hyphen)
  • .FirstName ❌ (starts with a dot)
  • Personnel. ❌ (ends with a dot)

Optional: No Underscores Allowed #

If your naming convention doesn't permit underscores, simply remove the _ from the regex:

^[A-Za-z][A-Za-z0-9]*(\.[A-Za-z][A-Za-z0-9]*)*$

内容的提问来源于stack exchange，提问作者Slava