Simple Array Program

This is a discussion on Simple Array Program within the C++ Programming forums, part of the General Programming Boards category; So i have to read in a list of rocket names and masses and print them out the rocket names ...

  1. #1
    Registered User
    Join Date
    Apr 2011
    Posts
    6

    Simple Array Program

    So i have to read in a list of rocket names and masses and print them out the rocket names and masses in the reverse order they were entered. The list is terminated by the value "END". However, "END" should not be part of the list and should not be printed out. Max number of rockets is 50. Where do I go from here?

    Code:
    #include <iostream>
    #include <string>
    #include <iomanip>
    using namespace std;
    
    // Main Program
    int main( )
    {
    	// Constant Declarations
    
    	// Variable Declarations
            string r_names [50];
    	double     mass[50];
            int                        i;
    	string              junk;
    
    	for(i = 0; i < 49; i++)
    	{
    		cout << "Enter a rocket name (END to end list): ";
    		getline(cin, r_names[i]);
    		if(r_names[i] != "END")
    		{
    			cout << "What is the mass of a " << r_names[i] << ": ";
    			cin >> mass[i];
    			getline(cin, junk);
    			}
    			if(r_names[i] == "END")
    			{
    			break;
    			}
    	}
    			cout << "The rocket's entered in reverse order are:" 
    				 << r_names[i] << setiosflags(ios::fixed) << setw(6)
    				 << mass[i] << endl;
                
    
    	cout << "\n\nEnd Program.\n";
    
    	return 0;
    }
    Last edited by Chemeng11; 05-01-2011 at 11:02 AM.

  2. #2
    Registered User
    Join Date
    May 2010
    Posts
    2,778
    Does the code compile without errors/warnings?

    If not post the complete error/warning message exactly as it appears in your development environment.

    If it does compile without errors, does it produce the desired output?

    If not what output does the program produce? What do you expect the output to be?

    Jim

  3. #3
    a_capitalist_story
    Join Date
    Dec 2007
    Posts
    2,651
    This will not read 50:
    Code:
    for(i = 0; i < 49; i++)
    Go for
    Code:
    for(i = 0; i < sizeof(r_names)/sizeof(r_names[0]); i++)
    Code:
    getline(cin, r_names[i]);
    Simple logic! Read into a separate variable and compare that to "END", and only add to the r_names array if it's not "END".

  4. #4
    Registered User
    Join Date
    Apr 2011
    Posts
    6
    Jim: The program prints out with no compiler errors:
    The rocket's entered in reverse order are:END
    -9255963134931783000000000000000000
    0000000000000000000000000000.000000.

    The string, if that's the correct term usage, END will end the list and place the rocket names and masses in reverse order.
    For example, I will enter:
    Alpha
    62
    Omega
    35
    Delta
    39
    END

    The rockets entered in reverse order are:
    Delta 39
    Omega 35
    Alpha 62

    Rags_to_riches: I do not understand the purpose of the second part with your modified version of the for loop. What will that do?
    Last edited by Chemeng11; 05-01-2011 at 11:05 AM.

  5. #5
    a_capitalist_story
    Join Date
    Dec 2007
    Posts
    2,651
    The loop as you've written it will only gather up to 49 entries, not the 50 you need. As I have written it, it will gather the number of entries that will fit in the array; that is, 50 entries, as specified. sizeof() returns the size of the variable given. In this case the size is 50 * the size of a string variable. Therefore, in order to get the number of entries in the array you must divide that value by the size of a string variable.

  6. #6
    Registered User
    Join Date
    Apr 2011
    Posts
    6
    rags_to_riches: Can you elaborate on the statement you made and possibly give an example?
    Simple logic! Read into a separate variable and compare that to "END", and only add to the r_names array if it's not "END".

  7. #7
    Registered User
    Join Date
    Apr 2011
    Posts
    6
    I finally got the program to work. Thank you for the help!

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. Seemingly simple array program yielding bizarre output
    By alter.ego in forum C Programming
    Replies: 7
    Last Post: 04-07-2011, 11:15 AM
  2. Simple program, simple problem
    By KAUFMANN in forum C Programming
    Replies: 5
    Last Post: 02-16-2011, 12:16 PM
  3. simple program, simple error? HELP!
    By colonelhogan44 in forum C Programming
    Replies: 4
    Last Post: 03-21-2009, 11:21 AM
  4. [Help] Simple Array/Pointer Program
    By sandwater in forum C Programming
    Replies: 3
    Last Post: 03-30-2007, 02:42 PM
  5. Array question on my simple program?
    By correlcj in forum C++ Programming
    Replies: 11
    Last Post: 10-21-2002, 02:16 PM

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21