RegEx -- String Dismissal

RegEx -- String Dismissal

If you want to match a word A in a string and not to match a word B. For example: If you have a text:

1. I have 3 pets - 2 dogs and a cat
2. I have 1 pet - a dog


If you want to search for lines of text that HAVE a dog for a pet and DOESN'T have cat you can use this regular expression:

^(?=.*?\bdog\b)((?!cat).)*$


It will find only second line:

2. I have 1 pet - a dog