There may be more problems, but for starters, note that string comparisons are done using the "equals" method in Java, not using the "==" operator. So wherever you have something like "if (src=="Clear")" you need to replace that with "if (src.equals("Clear")".
I'd also suggest you ask more focused questions. Most people who see "this doesn't work" and then 150+ lines of code are going to simply move on.
tell us SPECIFICALLY what doesn't work. Only post the relevant code.
Also, I hope you didn't write all this code in one go, and now this is the first time you've run it. the best way to write code is to write tiny little chunks, maybe as little as one line, and then compile/run/test it until you're SURE it works. only THEN should you do any more.
There are only two hard things in computer science: cache invalidation, naming things, and off-by-one errors
Joined: Mar 22, 2005
I'm just noticing that the "i" loop starts at 0 - that will cause "str.substring(0, i-1)" to throw an exception.
subject: problem with writing calculator application