I did the following program and get blank line after pressing <ENTER>

purpleburple · 08-21-2002, 01:52 AM

Hi. Fairly new to C. I was wondering if anyone can explain to me why this didn't work .

#include <stdio.h>

#define BUFF 256

int main(void){

char name[BUFF];
int i;

puts("Enter your FULL name and press <ENTER>");
gets(name);

for(i=0; name[i]!= '\0'; i++){
if(name[i] == ' '){
i = i-1;
}
}

printf("Your FULL NAME is: %s\nThere are %d characters in your
full name\n", name, i);

return 0;

}

I understand that I SHOULD NOT use gets as even the compiler GCC gave me a warning about using it but It was a simple program for demonstration purpose and I don't understand why it didn't work. It was supposed to display FULL name and count characters in 'name' excluding white space but I just get a new cursor after pressing <ENTER> and a blank line

thanks.

Malicious · 08-21-2002, 02:19 AM

Code:

for(i=0; name[i]!= '\0'; i++){
   if(name[i] == ' '){
	i = i-1;
   }
}

This should work as long as there is no space in the input.

However, once you find a space in the input, you decrement the loop counter; the end of the loop increments it and you continue at the same "i" value forever. Messing with the loop counter is normally a no-no, but there are occasions when you will want to.

purpleburple · 08-21-2002, 02:43 AM

oh!!! Cool!!! SO I see now. Once white space is hit 'i' goes down one and then is incremented and then goes down again and then up again etc. making an endless loop. Am I following you?

I should have maybe done it this way ..

int b=0;

for(i=0; name[i] != '\0'; i++){
if( name[i] == ' '){
b++;
}
}

/* now lets subtract white space from count of characteres */
i = i - b;

thanks alot malicious

Malicious · 08-21-2002, 03:08 AM

You got it...

What about:

Code:

for(i=0; name[i] != '\0'; i++){
    if (name[i] != ' ') 
        b++;
}

and just print b?

purpleburple · 08-21-2002, 11:55 AM

awesome ..... YEAH!!! that would make a little more sense ... and wouldn't that be a 'little' more efficient then the way I did it in program execution time??

Not that you'd ever notice on today's computer's or maybe even oldies ....

back to programming ......

purpleburple · 08-21-2002, 12:00 PM

actually no ... the program's intent was to 'count' the characters that the user enters 'excluding' white space so I'd have to subtract b from i I would think ..

im new .......