wizzard...(!)

This is a discussion on wizzard...(!) within the C Programming forums, part of the General Programming Boards category; I have this: Code: #include <stdio.h> main() { int d,choice; printf("gIVE 1 or 2 or 3 or 4 or 5 ...

  1. #1
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    wizzard...(!)

    I have this:

    Code:
    #include <stdio.h>
    
    main()
    {
    
                     int d,choice;
    
    
    		printf("gIVE 1 or 2 or 3 or 4 or 5 \n ");
    		
    		do{	
    			scanf("%d",&choice);
    			
    			
    			if(choice!=1 && choice!=2 && choice!=3 && choice!=4 && choice!=5)
    				printf("Plz, becareful ");
    
    		}while(choice!=1 && choice!=2 && choice!=3 && choice!=4 && choice!=5);
    
    }
    if i give an integer (7, 56,8..), it prints the message and it's waiting for a new entry. OK
    if i give a character, it prints the message continuesly! why????????

    thx!

  2. #2
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    The character takes the newline that scanf() leaves behind and says "I've got my char", and keeps on looping.

    it's always best to pull off the left over newline, as soon as possible (or as you need to if you know the in's and out's of scanf().

    add:
    somevariable = getchar() ready after the scanf() and you'll see the difference (don't use choice as your variable, of course).

  3. #3
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    Quote Originally Posted by Adak View Post
    The character takes the newline that scanf() leaves behind and says "I've got my char", and keeps on looping.

    it's always best to pull off the left over newline, as soon as possible (or as you need to if you know the in's and out's of scanf().

    add:
    somevariable = getchar() ready after the scanf() and you'll see the difference (don't use choice as your variable, of course).
    ok...

    but it prints the message many time, as the characters i give.

    for example
    i give sdf
    it prints the message 3 times...

    can i avoid this?

  4. #4
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    You lost me.

    Do you want to get a string of char's or a number, or ??

    for a string, use: scanf("%s", someCharArrayName)

    Before you use scanf() for a char, or for a string, you should have a clean keyboard buffer. for numbers, it won't matter - scanf() skips over "whitespace" when it's looking for a number.

    not true for char's or strings, though.

  5. #5
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    I just want to ensure, that the user will able to give only these entries : 1 or 2 or 3 or 4 or 5.

    Any other entry, is not acceptable.

  6. #6
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    try this, it is a little bit shorter

    Code:
    if( (choice <= 0) || (choice > 5) )

  7. #7
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    and what is

    Code:
    int d
    for?

  8. #8
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    Quote Originally Posted by Victor_November View Post
    and what is

    Code:
    int d
    for?
    Planning for the future, no doubt.

    I would use Victor's code in parentheses, but make it choice < 1 || choice > 5 instead, and remove the if part. Just use it for the while() test at the bottom of the loop.
    Last edited by Adak; 11-11-2009 at 04:49 PM.

  9. #9
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    Planning for the future, no doubt.
    exaclty!!!

    somevariable = getchar() ready after the scanf() and you'll see the difference (don't use choice as your variable, of course).
    what do you mean?

    i wrote this, but i have the same problem..
    Code:
    #include <stdio.h>
    
    main()
    {
    
                     int choice;
    
    
    		printf("gIVE 1 or 2 or 3 or 4 or 5 \n ");
    		
    		do{	
    			choice = getchar();
    			
    			choice = choice -48;
    			
    			
    			if(choice!=1 && choice!=2 && choice!=3 && choice!=4 && choice!=5)
    				printf("Plz, becareful\n ");
    
    		}while(choice!=1 && choice!=2 && choice!=3 && choice!=4 && choice!=5);
    
    }

  10. #10
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    Quote Originally Posted by johnybe View Post
    exaclty!!!

    i wrote this, but i have the same problem..
    This is what I meant:
    Code:
    #include <stdio.h>
    
    main()
    {
                     int choice, gar;
    
    		printf("gIVE 1 or 2 or 3 or 4 or 5 \n ");
    		
    		do{	
    			
                            scanf("%d", &choice);
      			
    			if(choice <1 || choice >5) {
    				printf("  Plz, becareful\n ");
                                    gar = getchar();
                            }
    		}while(choice < 1 || choice >5);
    
    }
    Last edited by Adak; 11-11-2009 at 07:06 PM.

  11. #11
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    Quote Originally Posted by adak View Post
    this is what i meant:
    Code:
    #include <stdio.h>
    
    main()
    {
                     int choice, gar;
    
    		printf("give 1 or 2 or 3 or 4 or 5 \n ");
    		
    		do{	
    			
                            scanf("%d", &choice);
      			
    			if(choice <1 || choice >5) {
    				printf("  plz, becareful\n ");
                                    gar = getchar();
                            }
    		}while(choice < 1 || choice >5);
    
    }
    thxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxx

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