Add two numbers

This tutorial will read in two numbers from the console line and output the answer of the two integer values.

The cin refers to the console input, the >> allows the console input value placed into the variable (in this case the val1, val2), NOTE. << would mean output. With using the exception, and the try catch block of code allows for any errors in the conversion of the input into a integer value. Within the printf, there are a few conversion types, the %d means using the corresponding parameter within printf and output a integer value, %s means a string. When I say the corresponding parameter, if there are two %d within the output string, it will display in order the values attached to the printf(...) call. The code

#include <iostream>
#include <exception>
 
//using the namespace std (standard) for the cin -> console input
using namespace std;       
 
int main()
{
       // setup the defaul values.
       int val1 =0, val2 =0;
       try 
       {
              // output to the console
              printf("Please enter number 1 : ");
              // read in the input, if not a integer value, this will
              // cause a error 
              cin >> val1;       
              printf("Please enter number 2 : ");
              cin >> val2;
       }
       catch (exception& e)
       {
              // write out any error exception
              printf("Not a valid input %s\n", e.what());
       }
       // output the answer of the two inputted values.
       printf("Answer : %d\n", (val1 + val2));
       return 0;
}

save this as cppaddtwonumbers.cpp. Once compiled (g++ cppaddtwonumbers.cpp -o cppaddtwonumbers (the -o means to output to the filename else a a.out file name would be created))
Once executed the program, cppaddtwonumbers within Windows, or ./cppaddtwonumbers within Linux/Unix.

The output would be

Please enter number 1 : 23
Please enter number 2 : 41
Answer : 64

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