C Programming - Pointers - Discussion

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char str1[] = "India";
char str2[] = "BIX";
char *s1 = str1, *s2=str2;
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Here str1 is array holding values as - >>
str1 ['I','n','d','i','a']
0 1 2 3 4
^
|
s1 // s1 is pointing to base address or
first element of array str1
And str2 is array holding values as - >>
str1 ['B','I','X']
0 1 2
^
|
s2 // s2 is pointing to base address or
first element of array str2
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while(*s1++ = *s2++)
printf("%s", str1);
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This while loop will be executed till there is some values in the array pointed by s1 and s2. or simply till '\0' is not encountered.

*s1++ = *s2++

The above statement means assign the value pointed by s2 into value pointed by s1;
Increment will be done after assignment because it is postfix operator.

As above statement is executed value pointed by s2(i.e. B ) is assigned to the location pointed by s1(i.e. atr1[0]).

str1 is having values as [B,n,d,i,a].
printf will print ---------->> Bndia.

On the second iteration.

As s1 and s2 are incremented they are now pointing to'n' and 'I' respectively.
Now in a similar way, and will be replaced by I.
And,

str1 is having values as [B,I,d,i,a]
printf will print ---------->> BIdia

Similarly on 3rd iteration,

str1 is having values as [B,I,X,i,a]
printf will print ---------->> BIXia

Therefore, the output is BndiaBIdiaBIXia.

I did not understand this, tell me clarity.

Thanks Mahendra.

Well done @Uttam.

I think it will be BIX.

The 1st letter of *s2++ is BIX = 'B'.

'B' is assigned to the 1st letter of S1 so it becomes Bndia.

After that *S2++ mens increment by +1 so the result is BI now replace with *S1++ first two letters are BIdia(dia) from S1 we assign S2 in S1 .after that increment *S2++ so the result is BIX and it replaced 3 letter with S1 and then print.

Hope you understand.

Thank you all.

Hello friends,

str1 values r stored in S1 , we r operating on S1, str1 values remain same kW,in pf statement we should print the values of str1, so str1 values should be "India " kw.

You are absolutely right @Sowmya.

str1 value must be "India" as output.

I think while need a condition but there is '='assignment operator that can only assign the value so. It couldn't run.