Create a calculator application that accepts a mathematical problem via JOptionPane and
displays the result using JOptionPane.
For example, a user enters 23 + 42 =. The output would be 65.
Allow for the following operators, +, -, /, *. The preference of operations will be from left to right. This means that if a
user enters 6 – 4 * 2, the answer is 6 – 4=2 times 2 = 4. The answer would be 4.
Extra credit, 50pts if you design the program the accepts parenthesis. If a user enters 6 – (4 * 2) the answer is -2.
Continue to accept user input until the user enters 999