newbie help needed plz

[mikedeuk]

Hi guys, Im a complete begginer and currently working through c for dummies to try and learn this language.

The trouble is there are a few mistakes in the book. Figuring these out myself is probably helping me learn but, mistakes with the more complex stuff are a nightmare when im trying to teach myself.

Im currently on this:
http://www.c-for-dummies.com/sourcecode/learn/madlib1.c

I have managed to compile and build the program. I no my source code is correct now as i have even swapped it with a official downloaded version and i get the same result. I have searched online and it seems to work for everyone else. But

For some reason my computer will not display a word for food!?
My output reads : "Don't touch that hairy !
I just vacuumed the couch!"

Any help will be appreciated as i don't want to skip anything! Thanks, Mike

[quzah]

1. You don't actually need the & before the name of an array there.
2. %s will only take a single word (it will stop on a space).
3. You hit enter after you type the first word, which gets left behind and consumed by the food line. Try adding a space before the % sign.

scanf( " %s", food );

4. According to your output, nothing is wrong:

My output reads : "Don't touch that hairy waffle!
I just vacuumed the couch!"

That's four things.


Quzah.

[mikedeuk]

Hi, Thanks for the help. You were quite right, I mistakenly added the missing word in my output(its been a stressful morning lol) Now edited.

But im afraid after using your tips and changing my code its still not working.
Could it be a problem with my compiler or software? It seems to work for everyone else.

Is this what they call bugs or debugging when you need to test programs on different machines?

[MK27]

Is this what they call bugs or debugging when you need to test programs on different machines?

Yes.

Another thing you can try here is this:

	printf("Enter an adjective:");		/* prompt */
	scanf("%s%*c",adjective);			/* input */
	printf("Enter a food:");
	scanf("%s%*c",food);
	printf("Enter a household chore (past tense):");
	scanf("%s%*c",chore);
	printf("Enter an item of furniture:");
	scanf("%s%*c",furniture);

%*c tells scanf to discard a single character, hopefully the '\n'. It's not the perfect solution, but IMO there is no such thing when using scanf() for keyboard input. fgets() is much better. If you then need to break the input down into various types, you can use sscanf() on the string read in by fgets().

[mikedeuk]

Thanks for the help. Still missing waffle though! lol

Maybe my mac or gcc compiler just dosnt work well with this code?
In which case i'll just skip onto the next chapter in the book and hope it soon explains fgets!

Any other tips for a begginer trying to learn C with books?
EDIT: Just seen your ad for "The C Book" so may also use that when i get time! ; )

[MK27]

Maybe my mac or gcc compiler just dosnt work well with this code?

It's more to do with the system itself. But if you use that and do exactly what were asked, without ever hitting the space bar, it should work.

The issue is that the input is buffered by the system, and what gets read from and left in that buffer.

But don't get too hung up on this right now; when you really need to get input correctly, you'll find a way, but you do need to understand some more choices first (like fgets).

The C Book is good, I think.

[mikedeuk]

I just had one final go and still no joy with:/*

insert

MADLIB1.C Source Code
Written by Dan Gookin
*/

#include <stdio.h>

int main()
{
	char adjective[20];
	char food[20];
	char chore[20];
	char furniture[20];

/* Get the words to use in the madlib */

	printf("Enter an adjective:");		/* prompt */
	scanf("%s%*c",&adjective);			/* input */
	printf("Enter a food:");
	scanf("%*s%*c",food);
	printf("Enter a household chore (past tense):");
	scanf("%s%*c",&chore);
	printf("Enter an item of furniture:");
	scanf("%s%*c",&furniture);

/* Display the output */
	
	printf("\n\nDon't touch the %s %s\n",adjective,food);
	printf("I just %s the %s!\n",chore,furniture);

	return(0);
}

I don't even understand why it only has a problem with the first output line, as the second also has 2 words but it works fine!
Anyway im going to give up and move on now before i get all together fed up with it!
Thanks for all your help, Im sure i'll be back soon!

[rags_to_riches]

Again...

scanf("%s%*c",&adjective);			/* input */
...
scanf("%s%*c",&chore);.
...
scanf("%s%*c",&furniture);

Get rid of the &s!

scanf("%*s%*c",food);

Why the * before the s?

[AndrewHunter]

Edit: Too slow

[mikedeuk]

Sorry, I thought you said the &s weren't necessary, I didnt realise you meant they were causing a problem. I did experiment removing 1 or 2 but it didnt make any difference!

I have now removed them all along with the extra * and....Your right it works!

Sorry it took me so long to get that right but, Many thanks! ; )

[CommonTater]

Your scanf syntax is all messed up...

/* Get the words to use in the madlib */

	printf("Enter an adjective:");		
	scanf("%s%*c",&adjective);	 	
	printf("Enter a food:");
	scanf("%*s%*c",food);
	printf("Enter a household chore (past tense):");
	scanf("%s%*c",&chore);
	printf("Enter an item of furniture:");
	scanf("%s%*c",&furniture);

Look up scanf() in your C library documentation and follow the guidelines...
For example... scanf("%s%*c",&furniture); ... should be... scanf("%s",furniture);

The & (address of) operator is not needed for strings, strings ARE pointers.
The attempt to ignore trailing spaces is of no value here. If you have problems with it skipping inputs, use getchar() after each scanf().

[quzah]

Or you could have done what I told you to do in my first reply:

Try adding a space before the % sign.

scanf( " %s", food );

Quzah.

[CommonTater]

Or you could have done what I told you to do in my first reply:
Quzah.

I knew that worked with %c... good to know it works with %s too...

[tabstop]

I knew that worked with %c... good to know it works with %s too...

(Ssshh: It doesn't, since %s already skips spaces at the beginning.)

[quzah]

(Ssshh: It doesn't

It works fine with the space.

, since %s already skips spaces at the beginning.)

So what you are saying is that he has no actual problem and he's making this all up? This works with our without the space:

#include<stdio.h>
int main( void )
{
    char words[4][ BUFSIZ ] = {{0}};
    int x;
    for( x = 0; x < 4; x++ )
    {
        printf( "enter a word, then hit enter: " );
        fflush( stdout );
        scanf( "%s", words[x] );
    }
    printf( "%s, %s, %s, %s\n", words[0], words[1], words[2], words[3] );
    return 0;
}

The space has no adverse effect.


Quzah.