Regex to match only two specific words, e.g. Yes or No

Question

My attempt is:

^Yes|^No|^$ 

but when I use this, words other than "Yes" and "No" are matched

How do I fix it?

I've been testing my regex using this online regex tester.

Answer 1

Try this:

^(?:Yes|No)$

In VBScript, something like this:

Dim myRegExp, FoundMatch
Set myRegExp = New RegExp
myRegExp.Pattern = "^(?:Yes|No)$"
FoundMatch = myRegExp.Test(SubjectString)

What was the problem?

You had an alternation with three options:

• ^Yes matches Yes at the beginning of the string, but will also match Yes in Yes, man...
• ^No matches No at the beginning of the string, but will also match No in No way!
• ^$ matches the empty string

Answer 2

Below regex would match yes or no only,

^(?:Yes\b|No\b)

Demo