How to match with an exact string using regular expression

Question

I have small requirement.I want to search a string with exact match. Suppose i want to search for None_1, i am searching for 'None_1' using /None_1/, but it is matching even "xxxNone" but my requirement is it should match only None_[any digit]. Here is my code

/^None_+[0-9]{?}/

So it should match only None_1 , None_2

Answer 1

You should also anchor the expression at the end of the line. But that alone will not make it work. Your expression is wrong. I think it should be:

/^None_[0-9]+$/

• ^ matches the beginning of a line
• [0-9]+ matches one or more digits
• None_ matches None_
• $ matches the end of a line

If you only want to match one digit, remove the +.

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Your original expression /^None_+[0-9]{?}/ worked like this:

• ^ matches the beginning of a line
• None matches None
• _+ matches one or more underscores
• [0-9] matches one digit
• {? matches an optional opening bracket {
• } matches }