C Programming - Pointers - Discussion

*s = base address of str.
Now s is pointing to p.

Since s++ is a post increment, it gets incremented 3 times, not before that. So s is pointing to c.

So it points from "ce".

#include<stdio.h>

int main()
{
char str[] = "peace";
char *s = str;
printf("%s\n", s++ +3);
printf("%s\n", s+3);
return 0;
}

Run this. You will know diff.

Actually s++ = s+1 here use this fundamental s++ +3 means s = s+3.

So the answer is ce.

In the pointers when we store the address of string. Like here s points to the str. on incrementing s i.e. s + 1, from the second position the string is printed i.e. if we do s + 1 then printf("%s",str) then "eace" is printed.

Does the same it holds for array ? I mean point a pointer 'p' to an array then we do p +1 then from there can the rest elements be printed?

Can any1 explain?

Actually What is happening here, s++ is the post increment. So the initial value of s is replacing s++ means first character and you adding +3 so it will go to 'c' and print remaining characters.

All this kind of expression which include + are calculated from right to left of (). thanks @Swathi.

int main()
{
char str[] = "peace";
char *s = str;
printf("%s\n", s++ +3);
return 0;
}

Here s points to str
s--->peace

s++ +3//s is post incremented so don't care about s in this line.
You must consider it as just s+3 which is equal to s[3].

@Kiran.

Hello, ++ has highest priority than '+'.watch following associativity & precedence table. because of the post increment, it first adds 3 in it & printf gets execute, after that post increment happens.

@Akshaya.

printf("%d\n", ++s +3); answer of this is: e
because os pre increment, it 1st increment to 'e' & adds 3 into it, that's why next 'e'.



Operators in order of precedence Associativity
(), [], ->, . left to right
!, ~, ++, -, - (unary), * (indirection), & (address-of), sizeof, casts right to left
* (multiplication), /, % left to right
+, - (subtraction) left to right
<<, >> left to right
<, <=, >=, > left to right
==, != left to right
& (bitwise and) left to right
^ left to right
| left to right
&& left to right
|| left to right
?: right to left
=, +=, -= etc. right to left
, left to right

Thanks monica.

@Monika : Thamk you so much for explaining in such a nice way.....