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![ Write a C++ program to find the sum of elements in an array using pointer.
#include <iostream.h>
#include <conio.h>
int main() {
clrscr(); // Clear the screen
int n;
cout << "Enter the number of elements in the array: ";
cin >> n;
if (n <= 0) {
cout << "Invalid input. Please enter a positive number of elements." << endl;
}
int arr[100]; // Assuming a maximum of 100 elements, adjust as needed
int *ptr = arr; // Pointer to the array
int sum = 0;
cout << "Enter the elements of the array:" << endl;
// Input the elements of the array
for (int i = 0; i < n; i++) {
cin >> *ptr;
sum += *ptr;
ptr++;
}
cout << "Sum of elements in the array: " << sum << endl;
getch(); // Wait for a key press to close the console
return 0;
}](https://image.slidesharecdn.com/pointer-240228183252-50165731/85/Pointers-in-c-programming-presentation-5-320.jpg)
Pointers in c++ programming presentation
- 1.
- 2. POINTER isa variable that holds the memory address of another variable. Ex: int a =10; Int* ptr=&a; Cout<<a; // a=10 Cout<<ptr; //ptr=1000 Cout<< *ptr;//*ptr=10 Cout<<&a; //a=1000
- 3. While workingwith operator we need two operator & address of operator * value at address operator
- 4. Write aC++ program that declares an integer variable, initializes it with a value, and then uses a pointer to change the value of that variable. #include <iostream.h> #include <conio.h> int main() { clrscr(); // Clear the screen int number = 42; // Declare and initialize an integer variable int *ptr; // Declare a pointer to an integer ptr = &number; // Assign the address of 'number' to the pointer 'ptr' cout << "Original value of 'number': " << number << endl; // Use the pointer to change the value of 'number' *ptr = 99; cout << "New value of 'number' using pointer: " << number << endl; getch(); // Wait for a key press to close the console return 0; }
- 5. Write aC++ program to find the sum of elements in an array using pointer. #include <iostream.h> #include <conio.h> int main() { clrscr(); // Clear the screen int n; cout << "Enter the number of elements in the array: "; cin >> n; if (n <= 0) { cout << "Invalid input. Please enter a positive number of elements." << endl; } int arr[100]; // Assuming a maximum of 100 elements, adjust as needed int *ptr = arr; // Pointer to the array int sum = 0; cout << "Enter the elements of the array:" << endl; // Input the elements of the array for (int i = 0; i < n; i++) { cin >> *ptr; sum += *ptr; ptr++; } cout << "Sum of elements in the array: " << sum << endl; getch(); // Wait for a key press to close the console return 0; }
- 6. Create afunction to find the square of a number using pointer #include <iostream.h> #include <conio.h> // Function to calculate the square of a number using pointers void square(int *ptr) { *ptr = (*ptr) * (*ptr); } int main() { clrscr(); // Clear the screen int number; cout << "Enter a number: "; cin >> number; // Call the square function to calculate the square using a pointer square(&number); cout << "Square of the number: " << number << endl; getch(); // Wait for a key press to close the console return 0; }
- 7. Create afunction to swap two numbers using pointers. #include <iostream.h> #include <conio.h> // Function to swap two numbers using pointers void swapNumbers(int *ptr1, int *ptr2) { int temp = *ptr1; // Store the value pointed to by ptr1 in a temporary variable *ptr1 = *ptr2; // Assign the value pointed to by ptr2 to ptr1 *ptr2 = temp; // Assign the value stored in the temporary variable to ptr2 } int main() { clrscr(); // Clear the screen int num1 = 10; int num2 = 20; cout << "Before swapping: num1 = " << num1 << ", num2 = " << num2 << endl; // Call the swapNumbers function to swap the values of num1 and num2 using pointers swapNumbers(&num1, &num2); cout << "After swapping: num1 = " << num1 << ", num2 = " << num2 << endl; getch(); return 0;
- 8. What isbasic difference between call by value and call by reference . any changes made to the parameter inside the function do not affect the original data outside the function. Call by value is suitable for situations where you want to protect the original data from being modified within the function. //Pass by value void modifyValue(int x) { x = x * 2; // Modifications to x don't affect the original value outside the function } int main() { int num = 5; modifyValue(num); // num is still 5 return 0; }
- 9. // passby reference void modifyReference(int &x) { x = x * 2; // Modifications to x directly affect the original value } int main() { int num = 5; modifyReference(num); // num is now 10 return 0; }
- 10. create afunction to swap two integer values using call by value #include<iostream.h> #include<conio.h> // Function to swap two integers using Call by Value void swapByValue(int a, int b) { int temp = a; a = b; b = temp; } void main() { clrscr(); // Clear the screen int num1 = 5; int num2 = 10; cout << "Before swapping:" << endl; cout << "num1 = " << num1 << endl; cout << "num2 = " << num2 << endl; // Call swapByValue function swapByValue(num1, num2); cout << "After swapping by value:" << endl; cout << "num1 = " << num1 << endl; cout << "num2 = " << num2 << endl; getch(); // Wait for a key press before exiting }
- 11. create afunction to swap two integer values using call by reference. #include<iostream.h> #include<conio.h> // Function to swap two integers using Call by Reference void swapByReference(int &a, int &b) { int temp = a; a = b; b = temp; } void main() { clrscr(); // Clear the screen int num1, num2; cout << "Enter the first integer: "; cin >> num1; cout << "Enter the second integer: "; cin >> num2; cout << "Before swapping:" << endl; cout << "num1 = " << num1 << endl; cout << "num2 = " << num2 << endl; // Call swapByReference function swapByReference(num1, num2); cout << "After swapping by reference:" << endl; cout << "num1 = " << num1 << endl; cout << "num2 = " << num2 << endl; getch(); }