You use look ahead assertions to check if a string contains a word or not.
If you want to assure that the string contains “Android” at some place you can do it like this:
^(?=.*Android).*
You can also combine them, to ensure that it contains “Android” at some place AND “Mobile” at some place:
^(?=.*Android)(?=.*Mobile).*
If you want to ensure that a certain word is NOT in the string, use the negative look ahead:
^(?=.*Android)(?!.*Mobile).*
This would require the word “Android to be in the string and the word “Mobile” is not allowed in the string. The .* part matches then the complete string/row when the assertions at the beginning are true.
See it here on Regexr