Question

I need to implement the following:

“$prefs” within the string “something something $prefs(something
something)” should be returned. $prefs consists of letters form a-zAz
and digits from 0-9. The “$” is always there.

Finding the beginning of $prefs is no problem, but finding the end is trickier. As described above, $prefs could also be $prefssdf, followed be pretty much anything, like (, ,, &&, and what not.

Is there a way to do something like this:

while(string.elementAt(i) == [a-zA-Z0-9]){
    result += string.elementAt(i);
}

An example:

I have following string:

Select * from test where $prefs(select * from test2 where $prefs2);

I need to extract all occurrences of expressions with $ prefixed, so in this case it is $prefs and $prefs2. How do I do that most efficiently?

Answer 1

  if(Character.isDigit(a) ||  (a  >=  'a' && a <= 'z' ) || ( a >= 'A' && a <= 'Z' )) {
         // a is [a-zA-Z0-9]
   }