Calculator Operation

Project 0 Activity

Instructions

In this activity you’ll implement a program to collect two operands from the user and act on them with an operator supplied by the user. Complete the following:

  • Write a program in src/5_calc_op.cpp so it performs the behavior specified below.

Just a reminder that std::cin >> my_variable will attempt to convert input text to a numeric value if my_variable is a number.

  • Hint: Mind the formatting!!!

Expected Behavior

This checkpoint assumes a potentially adversarial user who might not always enter values that directly adhere to the prompts. The user may enter incorrect values for operands, but will not type spaces and will not type more than one character for an operand. The user also always enters numbers correctly. Lucky you! The prompts should run as follows:

Program:

Please type a number and press enter:

User:

<response 1>

Program:

Please type a math operator (one of: + - * or /):

User:

<response 2>

Program:

Please type another number and press enter:

User:

<response 3>

At this point three things can happen depending on what the user entered. If the user has attempted to divide by zero, the program should output the below to stderr and return -1.

Error: Divide by zero attempted!!!

If the operand is not one of the four options given in the prompt the program should output the below to stderr and return -1.

Error: specified operation (<response 2>) not recognized.

Otherwise (if the operand is valid and there is no division by zero) the program should output the result of the operation and return 0.

Here's the result of the operation!
<response 1> <response 2> <response 3> = RESULT_OF_THE_OPERATION

Make sure to use float type variables to represent the operands. And finally, make sure to follow the formatting shown here down to the character!

Testing

All the code for this checkpoint can be tested by running the local unit tests. Make sure your code is built first. Then run ctest -R CalcOp --output-on-failure in the /build directory to test only the code for this checkpoint.

If you’re rusty on your arithmetic or trying to figure out which character you left out you can run your program with ./calc_op in the build directory.