Princess Nora University
Faculty of Computer and Information Science
CS 2 4 0
Part1: Paper-and-Pencil Exercises:
U
Trace and then choose the right answer a, b, or c:
U
1.
int a;
int* p;
a = 2;
p = &a;
a = a + 1;
cout << *p;
a) 2 b) 3 c) Won't run
2.
int a;
int* p;
a = 2;
p = a;
a = a + 2;
cout << *p;
a) 2 b) 4 c) Won't run
3.
int a;
int b;
int* p;
p = &a;
*p = 4;
p = &b;
*p = 3;
cout << a << “ “ << b;
a) 4 3 b) 3 3 c) Won't run
4.
int a;
int b;
int* p;
int* q;
a = 3;
p = &a;
q = p;
*q = *q + 5;
cout << *p;
a) 8 b) 3 c) Won't run
5.
int a;
int* p;
a = 4;
p = &a;
Page 1 of 5
Pointers
Self Study Exercises
Model Answer
Princess Nora University
Faculty of Computer and Information Science
CS 2 4 0
cout << (*p) / a;
a) 1 b) 4 c) Won't run
6.
string s;
string* p;
s = “Fred Jones”;
p = &s;
cout << *p;
a) Fred Jones b) Fred c) A hexadecimal memory address
7.
string s;
int* i;
s = “Fred Jones”;
i = &s;
cout << *i;
a) Fred Jones b) A garbage number c) Won't run
8.
void doubleref(int* p) {(*p) = (*p) * 2;}
int main()
{
int a = 5;
doubleref(&a);
cout << a;
}
a) 5 b) 10 c) Won't work
9. int a;
int b;
int* p;
int* q;
a = 3;
p = &a;
q = p;
b = 4;
*q = b;
cout << *p << a;
a) 4 3 b) 3 4 c) 4 4
10.
int a;
int* p;
a = 3;
p = &a;
cout << p;
a) 3 3 b) A hexadecimal memory address c) Won’t run
Page 2 of 5
Pointers
Self Study Exercises
Model Answer
Princess Nora University
Faculty of Computer and Information Science
CS 2 4 0
Pointers
Self Study Exercises
Model Answer
11.
int a;
int* p;
a = 4;
p = &a;
cout << (*p+1);
a) 4 b) 5 c) Random Garbage
12.
int a;
int* q;
a = 4;
q = &a;
cout << *(q+1);
a) 4 b) 5 c) Random Garbage
13.
Consider the following statements:
int *p;
int i;
int k;
i = 42;
k = i;
p = &i;
After these statements, which of the following statements will change the
value of i to 75?
a) k = 75;
b) *k = 75;
c) p = 75;
d) *p = 75;
e) Two or more of the answers will change i to 75
Page 3 of 5
Princess Nora University
Faculty of Computer and Information Science
CS 2 4 0
Pointers
Self Study Exercises
Model Answer
Part2: coding exercises:
U
For each of the following Exercises, use the pointer notation (*) ONLY. Do NOT
use the array index [] notation.
1. Write a function countEven(const int* a, int size) which receives an integer
array and its size, and returns the number of even numbers in the array.
Your main function should be as follows:
void main()
{
int a[]={10,13,15,20,22,17};
cout<<countEven(a, 6)<<endl;
}
#include<iostream>
using namespace std;
int countEven(const int * a, int n)
{
int counter = 0;
for(int i=0; i<n;i++)
if (*(a+i)%2==0)
counter++;
return counter;
}
void main()
{
int a[]={10,13,14,20,22,27};
cout<<countEven(a, 6)<<endl;
}
2. Write a function myStrLen(const char*) which returns the length of the
parameter cstring. Write the function without using the C++ function strlen.
Your main function should be as follows:
void main()
{
const char * myString = "Hello, I love pointers";
cout << myStrLen(myString)<<endl;
}
#include<iostream>
using namespace std;
int myStrLen(const char* a)
{
int i;
for (i=0; *a++!=NULL ; i++);
return i;
}
void main()
{
const char * myString = "Hello, I love pointers";
cout << myStrLen(myString)<<endl;
}
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Princess Nora University
Faculty of Computer and Information Science
CS 2 4 0
Pointers
Self Study Exercises
Model Answer
3. Write a function that returns a pointer to the maximum value of an array of
double's. If the array is empty, return NULL.
double* maximum(const double* a, int size);
Your main function should be as follows:
void main()
{
double a[]={10,50,14,20,94,27};
cout<<*maximum(a, 6)<<endl;
}
#include<iostream>
using namespace std;
double* maximum(double* a, int size)
{
double * max = a;
for (int i=1; i<size; i++)
if(*(a+i)>*max)
*max = *(a+i);
return max;
}
void main()
{
double a[]={44,50,14,20,94,27};
cout<<*maximum(a, 6)<<endl;
}
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