Question

I am new to regular expressions and need some help.

I have these sentences:

this is a-word
a word this is
aword is this
AWord is this
A-WORD is this

I’d like to know if the word a word or a-word or aword or AWord or A-WORD is in the sentence.

I tried this:

String sentence = "AWord is this";
String regex = "(a(\\s,'-','')word)\\i";
if (sentence.matches( regex)){
  .....
}

Answer 1

Try

a[^\w]?word

This will match any a followed by anything but a char, followed by word.

To match a narrower range of strings use [-\s]

Put (?i) at the beginning of the regex to make it case insensitive

(?i)a[^\w]?word

(reference, search here for other ways to search strings in a case insensitive way)

and remember to escape the \ to \\

The “safest” way is however to use this one

((a word)|(a-word)|(aword)|(AWord)|(A-WORD))

because it will match exactly what you need (if you know the exact domain of what you are looking for)