Pointer declaration - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of pointer declaration and usage

What is the output of this C code snippet?

C

#include <stdio.h>

int main() {
    int x = 10;
    int *p = &x;
    printf("%d\n", *p);
    return 0;
}

A Address of x

B 0

C 10

D Compilation error

💡 Hint

Remember that *p means the value pointed to by p.

The pointer p stores the address of x. Using *p accesses the value of x, which is 10.

❓ Predict Output

intermediate

Value of pointer variable after declaration

What is the value of the pointer variable p after this code runs?

C

int x = 5;
int *p = &x;

A Undefined value

B The address of x

C The value 5

D NULL

💡 Hint

Pointers store addresses, not values directly.

The pointer p is assigned the address of x using &x, so p holds x's address.

📝 Syntax

advanced

Identify the correct pointer declaration

Which of the following is a correct declaration of a pointer to an integer?

A int *p;

B int p*;

C int &p;

D pointer int p;

💡 Hint

The asterisk * goes before the pointer name to declare a pointer.

In C, 'int *p;' declares p as a pointer to an int. Other options are invalid syntax.

🧠 Conceptual

advanced

Pointer declaration with multiple variables

What is the type of variables a and b after this declaration? int *a, b;

A a is a pointer to int; b is an int

B a and b are both pointers to int

C a and b are both ints

D a is an int; b is a pointer to int

💡 Hint

The asterisk applies only to the variable it precedes.

Only a is declared as a pointer to int. b is a normal int variable.

🔧 Debug

expert

Find the error in pointer declaration

What error does this code produce? int *p; *p = 10;

C

int *p;
*p = 10;

A No error, prints 10

B Compilation error: missing semicolon

C Type error: incompatible types

D Segmentation fault or undefined behavior

💡 Hint

p is declared but not initialized before dereferencing.

Pointer p is uninitialized and points to an unknown location. Writing *p = 10 causes undefined behavior or crash.