Difference between revisions of "C Questions on Pointers"

Revision as of 21:04, 15 June 2014

<quiz display="simple"> {What will be the output of the following code? <syntaxhighlight lang="c">

1. include<stdio.h>

int main(){

 int a = 5;
 int* p = &a;
 printf("%d", ++*p);

} </syntaxhighlight> |type="{}" /} { 6 } ||p is pointing to the address of a. *p will return the content of a which is 5 and ++ will increment it to 6.

{What will be the output of the following code? <syntaxhighlight lang="c">

1. include<stdio.h>

int main(){

 char a[] = "Hello World";
 char* p = &a;
 printf("%s", p+2 );

} </syntaxhighlight> |type="()" /} -Compiler Error -World +llo World -Runtime Error

||Since p is a char pointer p+2 will add 2 to p (since sizeof(char) is 1). So, p+2 will be pointing to the string "llo World"

{What will be the output of the following code? <syntaxhighlight lang="c">

1. include<stdio.h>

int main(){

 int a;
 int* p = &a;
 printf("%zu", sizeof( *(char*)p  ));

} </syntaxhighlight> |type="()" /}

+1 -2 -4 -Compile Error

||p is typecasted to char pointer and then dereferenced. So, returned type will be char and sizeof(char) is 1

</quiz>