Loop trouble

This is a discussion on Loop trouble within the C++ Programming forums, part of the General Programming Boards category; First off this website has been my saving grace so far for my intro to C++ class. Basically here is ...

  1. #1
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    Loop trouble

    First off this website has been my saving grace so far for my intro to C++ class.

    Basically here is where i'm at:

    My instructions are to:

    Write a program solution to print all integer values between 1 and n that are multiples of 5 (i.e. evenly divisible by 5). This should be done with nested while loops. An inner while loop is controlled by a conditional expression determining when the last value for a particular n has been printed. An outer while loop should allow the user to enter a value, provide output for it, and then decide if he will enter a new value or quit.

    So far my code is:

    Code:
     #include <iostream>
    
    using namespace std;
    
    int main()
    {
    	int x,a=0;
    	char choice;
    
    	do
    	{
    		system ("cls");
    		cout<< " Enter a number to see all multiples of 5 "<<endl;
    		cin>> x ;
    		cout<<" Multiples " << endl;
    		while (x>=a)
    		
    		{
    			cout<< a << endl;
    			a=a+5;
    			
    		}
    	
    		cout<< " Try another number? Enter Y/N " <<endl;
    		cin>> choice;
    	
    	}	
    	while (choice == 'Y' || choice == 'y');
    
    	
    
    }
    The problem I am having is when I enter Y to run another number, and enter my new number, it doesnt count multiples of 5 from zero, it starts off where I left off on the previous program.

    I just dont know where to go from here.

    Thanks for any help!

  2. #2
    Jack of many languages Dino's Avatar
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    Reset variable "a" inside your loop.
    Mac and Windows cross platform programmer. Ruby lover.

    Quote of the Day
    12/20: Mario F.:I never was, am not, and never will be, one to shut up in the face of something I think is fundamentally wrong.

    Amen brother!

  3. #3
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    Wow, Simply amazing!

    If you were sitting next to me i'd buy you a beer (or whatever you like to drink)

    I cant believe how simple that was!

    Thanks, It is really appreciated!

  4. #4
    Cat without Hat CornedBee's Avatar
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    There's an important lesson here: Declare your variables as close to first use as possible.

    You never use a (or x) outside the do...while loop, so you should declare them inside. If you had done that, the problem would never have occurred.

    Instead, it seems that you learned to put all variable declarations at the start of the function. Some people consider it good style, but it's really a relic from C. In C++, you declare variables at the last possible location.
    All the buzzt!
    CornedBee

    "There is not now, nor has there ever been, nor will there ever be, any programming language in which it is the least bit difficult to write bad code."
    - Flon's Law

  5. #5
    Jack of many languages Dino's Avatar
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    Quote Originally Posted by peter94 View Post
    Wow, Simply amazing!

    If you were sitting next to me i'd buy you a beer (or whatever you like to drink)

    I cant believe how simple that was!

    Thanks, It is really appreciated!
    For remote fans, I usually suggest an iTunes gift card.
    Mac and Windows cross platform programmer. Ruby lover.

    Quote of the Day
    12/20: Mario F.:I never was, am not, and never will be, one to shut up in the face of something I think is fundamentally wrong.

    Amen brother!

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