Thread: Question about functions

I tried to make a code reverser like to reverse ur name from like David to divad
but it keeps getting same name not reversed

Code:

#include <stdio.h>
char namee(char name[])
{
	int x;
	for(x=5;x<=0;x--)
		;
	return 0;
}
int main(void)
{
char name[5];
fputs("please enter your name: ",stdout);
fgets(name,6,stdin);
namee(name);
printf("Now name reversed is %s",name);
return 0;
}

Maybe you should put something in the for loop, rather than doing absolutely nothing (well you're counting down from 5 to 0, but that's not that exciting).

oh yah forgot about name[x] lolz
but still didnt work out:S

Code:

#include <stdio.h>
char namee(char name[])
{
	int x;
	for(x=5;name[x]<0;x--)
		;
	return 0;
}
int main(void)
{
char name[5];
fputs("please enter your name: ",stdout);
fgets(name,6,stdin);
namee(name);
printf("Now name refersed is %s",name);
return 0;
}

but it still didnt work out

Do you expect name[x], which is a letter, to be less than zero? Really?

And even if it is, do you (still) expect your for loop to actually do anything?

why it run from 5 then -- to 0 ? so it will run reverse the name ?

Right now it doesn't run.

The first version did run, at least. It didn't do anything, but it would run. The second version, if it ran, wouldn't do anything either. If you want to do something in the function, like change name, you should probably do so instead of hoping it happens somehow.

I like using a left and right variable, together with a temp char, and swap them while left is less than right. Left being started at 0 and right being started at the last letter.

Since the char array may very well be larger than the name it's holding, I use something like this, to set right up, before the for loop that makes the exchange:

Code:

right = Max; // where Max is the size of the name array
while(name[--right] == '\0');

That puts right, right on the last letter, no matter the number of char's in name, or the size of the name array. Note the semi-colon at the end of that line.

The swap itself is the same as a swap in a sort:

temp = name[left]
name[left] = name[right]
name[right] = temp
--right;

left is incremented in the for loop itself.

finally did it thanks adak for poiting me to some stuff

Code:

#include <stdio.h>
#include <string.h>
input(){
	char name[5];
int i;
fputs("Please Enter your name: ",stdout);
fgets(name,6,stdin);
for (i=strlen(name); i >= 0; i--) { 
	printf("%c", name[i]);
}
}
int main(void)
{
input();
return 0;
}
}