Command Line Calculator Program

Abstract

This project is a Command Line Calculator capable of performing basic mathematical operations like addition, subtraction, division, and multiplication. The calculator appends operations to the current result unless the user requests a reset. It has been developed with a focus on good usage of OOP design, C++ STL, and follows clear naming and coding guidelines.

Functional Requirements

1. Validate Input: Ensure that all user inputs are valid numbers or operators.
2. Output on "=": Display the result of the current equation when the user inputs =.
3. Reset on "C": Clear the current equation when the user inputs c or C.
4. Exit on "Q": Exit the program when the user inputs q or Q.
5. Show Current Equation: Display the current equation in memory when the user inputs s or S.

Example Use Case

Current Equation in Memory (not displayed on console)
Enter number or operator: 12 ()
Enter number or operator: + (12)
Enter number or operator: 34 (12 + 34)
Enter number or operator: 45 (45)
Enter number or operator: = (45)
Current val = 45
Enter number or operator: / (45)
Enter number or operator: / (45/)
Invalid operator, enter again
Enter number or operator: s (45/)
Current equation is: 45/
Enter number or operator: 23 (45/23)
Enter number or operator: = (45/23)
Current val = 1.956521739
Enter number or operator: + (45/23)
Enter number or operator: 49 (45/23 + 49)
Current val = 50.956521739 (45/23 + 49)
Enter number or operator: * (45/23 + 49)
Enter number or operator: 3 (45/23 + 49 * 3)
Enter number or operator: = (45/23 + 49 * 3)
Current val = 148.956521739 (45/23 + 49 * 3)
Enter number or operator: C (Clears the equation)
Enter number or operator: 1 ()
Enter number or operator: q (Exits the program)
Exiting command line calculator. Thank you.

Key Features

• Basic Operations: Addition, subtraction, division, multiplication.
• Continuous Calculation: Appends the next operation to the current result unless reset.
• Input Validation: Ensures valid operators and numbers.
• User Commands:
  • =: Evaluate the current equation.
  • c/C: Clear the current equation.
  • q/Q: Exit the program.
  • s/S: Display the current equation in memory.

OOP Design & C++ STL

This project emphasizes a well-structured Object-Oriented Design to enhance maintainability and extensibility, leveraging C++ Standard Template Library (STL) for efficient management of data and operations.

How to Run

• Compile the code using a C++ compiler.
• Execute the program and follow the prompts to enter numbers and operators.