I have a calculator project.
My plus-button has a few statements.
-Statement 1 avoids typing 2 operators in a row.
-Statement 2 adds a "+" sign if there is no previous "+" sign.
-The last is to avoid adding a "+" sign while the <calculation>
string is empty(this string holds all user input).
It gives me an "java.lang.StringIndexOutOfBoundsException: length=0; index=-1"
error whenever I tap the plus-button. Someone know how to fix it?