In Java, when we try to do pattern matching using a regular expression. e.g. take a input string and use regular expression to find out if it is numeric. If not, throw an exception. In this case, I understand, using regex makes the code less verbose than if we were to take each character of the string, check if it is a number and if not throw an exception.
But I was under the assumption that regex also makes the process more efficient. IS this true? I cannot find any evidence on this point. How is regex doing the match behind the scenes? IS it not also iterating over the string and checking each character one by one?