Simple question about word reversing program

[amadeus111]

#include <stdio.h>


int main()
{
	char s[40], gecici;
	int  i, n;
	
	
printf("write a word : ");
	scanf("%s",s);
	
	for(n=0; s[n] != '\0'; n++);
	
	for(i=0; i<n/2; i++){        /*I didn't understand why we                         

                                         have to put "n/2" as the         

                                                   condition */
		gecici   = s[n-i-1];
		s[n-i-1] = s[i];
		s[i]     = gecici;
	}
	
printf("reverse         : %s\n",s);
	
return0;
}

this is not my code it works fine and everything I am just trying to understand the logic of the code. I have no idea why we put "n/2" as the condition. if I put "n-1" it still works too. I got everything else though.

[std10093]

[CODE] if I put "n-1" it still works too.

Input GeorgeSamarasDIT

You need n/2, because you have to go until the middle!

• you go along the word
• pick first letter and swap it with last letter
• Now the last is first and the first is last
• pick 2nd letter and swap it with prelast letter
• Now the prelast is second and the second is prelast
• ....

Think about it. Then scroll down.
.
.
.
.
..
.
.
.
You have to go until the middle of the word

//welcome to the forum!

[amadeus111]

Thank you! It makes sense now!

[std10093]

You are welcome

[nonpuz]

for(n=0; s[n] != '\0'; n++);

Most people use a nice little routine called "strlen()" it results in much more readable code. When I first glanced at this code I said "this loop does absolutely nothing...". The highest priority when writing code is READABILITY.

[std10093]

You should practise more if you saw that with first glance.

Also, for a beginner it just ok to use it like this.

He probably haven't use string.h yet!