"Expression result unused" Help?!

Discussion in 'Mac Programming' started by raaron1990, Oct 1, 2012.

  1. raaron1990, Oct 1, 2012
    Last edited by a moderator: Oct 1, 2012

    macrumors newbie

    Joined:
    Oct 1, 2012
    Location:
    Los Angeles, CA
    #1
    Hi all,

    Hopefully someone can help me out. I'm new to programming, and for class, we have to make a program that determines the day of the week of a specific date that the user enters. I keep getting an error "expression result unused" and I can't figure out why. Here's part of my source code:

    Code:
    int month, day, years, LTYear, total, Gtotal;
        
        cout<<"Input date in M/DD/YYYY format. (ex. 2/07/1990 or 10/13/2010)"<<endl;
        cin>>month; day; years;
        
        if (month==2 && years%4==0 && years%100!=0 && day>=30)
            cout<<"Invalid day.\n";
        else if (month==2 && day>=29)
            cout<<"Invalid day.\n";
        
        if (day<=1||day>31)
            cout<<"Invalid day.\n";
        
        if (years<1900 || years>2099)
            cout<<"Invalid year.\n";
    I get the issue when I try to get the cin for day and year. Any advice?

    Thanks in advance!
     
  2. knightlie, Oct 1, 2012
    Last edited: Oct 2, 2012

    macrumors 6502a

    Joined:
    Feb 18, 2008
    #2
    I'm not a C programmer, but this:
    Code:
    cin>>day; month; year;
    looks wrong to me - that appears to be three statements:
    Code:
    cin>>day;
    month;
    year;
    
    A semi-colon marks the end of a statement. The compiler is complaining that the month; and year; statements do not do anything. Maybe it should be:
    Code:
    cin>>day, month, year;
    
    Edit: Yes, the cin line is incorrect. As this is for class I won't give you the answer ( ;) ), but you need to change that line to be able to populate multiple variables.
     
  3. macrumors G5

    gnasher729

    Joined:
    Nov 25, 2005
    #3
     

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