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Looking for a new challenge to build upon your basic C++ coding experience? Start with step one to make a basic addition, subtraction, multiplication, and division calculator using C++ coding.

  1. Create source file to start writing C++ program.
  2. Begin writing in source file, using #include declare headers iostream and iomanip and using the identifier, using namespace declare std;.
     #include 
     <iostream> 
      
     #include 
     <iomanip> 
      
     using 
     namespace 
     std 
     ; 
    

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  3. Create the main statement you are going to write the code in. Add the return statement at end of code in the main function.
     int 
     main 
     () 
     { 
     return 
     0 
     ; 
     } 
    
  4. Begin code between brackets of the main statement before the return statement. Declare int variables num1 and num2, and char variable opr.
     int 
     num1 
     , 
     num2 
     ; 
     char 
     opr 
     ; 
    
  5. Use the cout command to prompt the user to enter two numbers. Using cin Assign the input to variables num1 and num2.
     cout 
     << 
     "Enter two integers: " 
     ; 
     cin 
     >> 
     num1 
     >> 
     num2 
     ; 
    
  6. Use the cout command to prompt user to enter an operator for the equation. Using cin assign the input to the char variable, opr.
     cout 
     << 
     "Enter operator: + (addition), - (subtraction)," 
     << 
     " 
     * 
     ( 
     multiplication 
     ), 
     / 
     ( 
     division 
     ) 
     : 
     "; 
     cin 
     >> 
     opr 
     ; 
     cout 
     << 
     endl 
     ; 
    
  7. Use cout to output results of what was entered then begin switch statement to find the result.
     cout 
     << 
     num1 
     << 
     " " 
     << 
     opr 
     << 
     " " 
     << 
     num2 
     << 
     " = " 
     ; 
     switch 
     ( 
     opr 
     ){ 
     } 
    
  8. Make case statement for when the user wants to do addition using case, use cout to output the product of num1 + num2, end the case with break.
     case 
     '+' 
     : 
     cout 
     << 
     num1 
     + 
     num2 
     << 
     endl 
     ; 
     break 
     ; 
    
  9. Make case statement for when the user wants to do subtraction using case. Use cout to output the product of num1 - num2, and end the case with break.
     case 
     '-' 
     : 
     cout 
     << 
     num1 
     - 
     num2 
     << 
     endl 
     ; 
     break 
     ; 
    
  10. Make case statement for when the user wants to do multiplication using case. Use cout to output the product of num1 * num2, and end the case with break.
     case 
     '*' 
     : 
     cout 
     << 
     num1 
     * 
     num2 
     << 
     endl 
     ; 
     break 
     ; 
    
  11. Make case statement for when the user wants to do division. For this case though you have to use an if and else statement in case the user tries to divide by zero, if the number is not zero use cout to output the product of num1 / num2, else if it is zero use cout to output a statement letting the use know the problem.
     case 
     '/' 
     : 
     if 
     ( 
     num2 
     != 
     0 
     ) 
     cout 
     << 
     num1 
     / 
     num2 
     << 
     endl 
     ; 
     else 
     cout 
     << 
     "ERROR 
     \n 
     Cannot divide by zero" 
     << 
     endl 
     ; 
     break 
     ; 
    
  12. Include the default statement within the switch structure. Default statement lets the user know when variables enter are not the correct operators. End the switch after the default statement.
     default 
     : 
     cout 
     << 
     "Illegal operation" 
     << 
     endl 
     ; 
     } 
    
  13. Go to the build menu on the top of the screen and click build program, then press ctrl 5 on the keyboard to run it. If there are errors the compiler will show their location.
    • Here is the final code:
       #include 
       <iostream> 
        
       #include 
       <iomanip> 
        
       using 
       namespace 
       std 
       ; 
       int 
       main 
       () 
       { 
       int 
       num1 
       , 
       num2 
       ; 
       char 
       opr 
       ; 
       cout 
       << 
       "Enter two integers: " 
       ; 
       cin 
       >> 
       num1 
       >> 
       num2 
       ; 
       cout 
       << 
       endl 
       ; 
       cout 
       << 
       "Enter operator: + (addition), - (subtraction)," 
       << 
       " * (multiplication), / (division): " 
       ; 
       cin 
       >> 
       opr 
       ; 
       cout 
       << 
       endl 
       ; 
       cout 
       << 
       num1 
       << 
       " " 
       << 
       opr 
       << 
       " " 
       << 
       num2 
       << 
       " = " 
       ; 
       switch 
       ( 
       opr 
       ){ 
       case 
       '+' 
       : 
       cout 
       << 
       num1 
       + 
       num2 
       << 
       endl 
       ; 
       break 
       ; 
       case 
       '-' 
       : 
       cout 
       << 
       num1 
       - 
       num2 
       << 
       endl 
       ; 
       break 
       ; 
       case 
       '*' 
       : 
       cout 
       << 
       num1 
       * 
       num2 
       << 
       endl 
       ; 
       break 
       ; 
       case 
       '/' 
       : 
       if 
       ( 
       num2 
       != 
       0 
       ) 
       cout 
       << 
       num1 
       / 
       num2 
       << 
       endl 
       ; 
       else 
       cout 
       << 
       "ERROR 
       \n 
       Cannot divide by zero" 
       << 
       endl 
       ; 
       break 
       ; 
       default 
       : 
       cout 
       << 
       "Illegal operation" 
       << 
       endl 
       ; 
       } 
       return 
       0 
       ; 
       } 
      
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Community Q&A

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Add New Question
  • Question
    How can I use C++ to create scientific calculator?
    Community Answer
    Code is too long to put here. Try asking the question on stackoverflow, where people have the space to write out code. I suggest (if you're really passionate) you learn C++ and make the code yourself. It won't be a hard code (some people write one as they learn C++).
  • Question
    How do I make this calculator output to two decimal places?
    Community Answer
    Press the S-to-D button, or just put a 0 at the end.
  • Question
    Can I make games using C++ coding?
    Community Answer
    Yes. C++ is a very good language to create a game in. Although it will be more difficult than a language like Java, it will be much faster and more efficient.
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      Tips

      • If code will not run make sure ; is after the correct statements and : is after each case.
      • If program is running but answers are not correct make sure break; is after each case statement.
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      Things You'll Need

      • Computer
      • C++ compiler (Examples use Visual Basic)

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