regex ekki innihalda
^((?!word).)*$
// Test
/^((?!word).)*$/gi.test('Should not contain word') // Returns false
/^((?!word).)*$/gi.test('John Doe') // Returns true
Regex ekki inniheldur
^((?!hede).)*$
regex ekki inniheldur
^(?!keyword).*\n // Regex pattern to find lines that do not contain keyword, incl newline