Thread: Processing Char and Int with the input

I can't seem to process the input correctly. This program here works fine, but I need to add the ability to be able to capture either a single INT variable, or a CHAR then an INT, and I'm not sure how to do that. Here's a sample program of what I'm trying to do.

Code:

#include <iostream>
using namespace std;

int get_input( )
{
    char input[30];
    char *end_ptr;
    int var;

    for ( ; ; )
    {
        fflush(stdout);
        fgets(input, sizeof input, stdin);        
        errno = 0;
        var = strtol(input, &end_ptr, 0);
            
        if ( end_ptr == input )
           cout << "Not a valid numeric input." << endl;
        else if ( input[0] == '\n' || ERANGE == errno )
           cout << "Not a valid number." << endl;
        else
            break;
    }
    
    return var;
}
int main( )
{
    int x, y;
    int MyTemp = 0;
    int MyValue[10] = {};

    for ( x = 1; x <= 10; x++ )
    {
        system( "cls" );
        cout << "Please enter the Temperature." << endl;
        cout << "Then enter 10 more Values." << endl << endl;
        cout << " TEMP: " << MyTemp << endl;
        for ( y = 1; y <= 10; y++ )
          cout << y << ": " << MyValue[y] << endl;
        
        if ( MyTemp == 0 ) // Temp cannot equal 0
        {
          cout << endl << "TEMP: ";
          MyTemp = get_input();
          --x;
          continue;
        }
        
        cout << endl << x << ": ";
        MyValue[x] = get_input();
    }
    
    return EXIT_SUCCESS;
}

You are first asked for a temperature, then 10 values. The part I cannot figure out is, in the get_input function I need a way to analyze the incoming input and see if it is just a numeric value, if so, "return var" just like normal so it can be entered in. But I need two commands that can be entered at any time, "Temp ###". Example...

Please enter the Temperature.
Then enter 10 more Values.

TEMP: 100
1: 1056
2: 2010
3: 1021
4: 4019
5: 0
6: 0
7: 0
8: 0
9: 0
10: 0

5: temp 109

When you at entering the 5th value, you can go back, change the value of the temperature, and continue along like nothing ever happened. I've tried a few different examples, but most ended up looking something like

cin >> variable1 >> variable2

And that doesn't work very well when for the most part you are entering single numbers. Any help out there please!

I'm not sure if I fully understand what you want, but if you want the user to be able to go back to a previous value, perhaps you could ask what value they want to change every time or just at the end. Something like:

Input the value you would like to change: 5
Input the value for 5: 26

And, to my knowledge, there's no easy way to check weather the user entered a char or a numerical character. I did a little test, and when you input a character when an int is expected, the computer thinks you pressed a very large number (30000+), so you could check that the number inputed is in a given range. Alternatively, you could complicate things even more with the getche() function.

I would use getline to read in a line at a time, and use sscanf or a similar function on it for simple parsing.