F5-IndexOf various characters at once

Hello!
Is there a way to check if a string contains different characters in just one line?

//this would be for just a:
if (stringAnalyzed.indexOf(“a”)!=-1){
//whatever actions;
}

//what If I want to check different ones inside that same conditional?
if (stringAnalyzed.indexOf(“a”|| “b”)!=-1){
//whatever actions;
}
I know this doesn’t work. What is the right syntax?
thanx:toad: