The application must be a GUI application, allowing the user to enter operands (the numbers) and operators as a string into the display window.
When the user clicks the “Calculate” button, the application will attempt to perform the calculation. If it cannot, an appropriate error should be displayed. Examples of exceptions would be a division by zero attempt, or an incorrectly formed postfix string for an equation.
The user can only enter numbers using the buttons on the calculator. He/she may not use the keyboard to enter the numbers or operators.
12 фрілансерів(-и) готові виконати цю роботу у середньому за $38
It will be like calculator and only way to enter is via buttons. There will be separate error label where it explains the error in case postfix has problem or has calc problems like division by 0. It is almost ready