Can a string object change to a expression and get the result?
For example a string "1+2+3" make someway to a result "6".
I want to make a calculator like "calc" in windows.
Have those features:
1.Show input expression on the screen in text object.
2.Can add & delete a word ("0~9" or "+-*/") of the end of expression anytime.
3.When press "=" button , get the result of the expression.
So can I make the string to expression like "eval" dose ?