Table of Contents
Swap function
A swap function is a function that allows you to exchange the values of two variables. It takes two variables as input and swaps their values. The purpose of a swap function is to provide a convenient and reusable way to perform the swapping operation.
How to swap
Swapping the values of two variables using a third variable involves the following concept:
- Declare the variables: Start by declaring the two variables that you want to swap, let’s call them
variable1andvariable2. Assign the initial values to these variables. - Display initial values (optional): You can choose to display the initial values of the variables before swapping to verify their current values.
- Declare a third variable: Declare a third variable, commonly named
temp, to temporarily hold the value of one of the variables during the swapping process. - Assign value of variable1 to temp: Assign the value of
variable1totemp. This step ensures that the value ofvariable1is saved before it gets overwritten during the swapping process. - Assign value of variable2 to variable1: Assign the value of
variable2tovariable1. Now, bothvariable1andvariable2hold the same value. - Assign value of temp to variable2: Assign the value of
temptovariable2. This step effectively swaps the value ofvariable2with the original value ofvariable1that was saved intemp. - Display swapped values (optional): Finally, you can choose to display the swapped values of the variables to confirm that the swapping process was successful.
C program that swaps the values of two variables using a third variable:
Example in c
#include<stdio.h>
void swap(int *a, int *b) {
int temp = *a;
*a = *b;
*b = temp;
}
int main() {
int x = 10;
int y = 20;
printf("Before swapping:\n");
printf("x = %d\n", x);
printf("y = %d\n", y);
swap(&x, &y);
printf("\nAfter swapping:\n");
printf("x = %d\n", x);
printf("y = %d\n", y);
return 0;
}
Output
Before swapping: x = 10 y = 20 After swapping: x = 20 y = 10
In this example, the swap function takes two integer pointers (int *a and int *b) as parameters. It uses the same swapping logic we discussed earlier: it stores the value of *a in a temporary variable, assigns the value of *b to *a, and then assigns the value of the temporary variable to *b. By using pointers, the function can modify the values of the original variables passed as arguments.
In the main function, two variables x and y are declared and assigned initial values. The swap function is then called with the addresses of x and y (&x and &y) as arguments. This allows the function to directly modify the values of x and y, effectively swapping their values. Finally, the swapped values are displayed.
Example in python
# Swapping values of two variables using a third variable
# Input values
a = 10
b = 20
# Displaying initial values
print("Before swapping:")
print("a =", a)
print("b =", b)
# Swapping logic
temp = a
a = b
b = temp
# Displaying swapped values
print("\nAfter swapping:")
print("a =", a)
print("b =", b)
Output
Before swapping: a = 10 b = 20 After swapping: a = 20 b = 10
In this program, we use a third variable called temp to temporarily store the value of one of the variables while swapping their values. The value of a is stored in temp, then b is assigned to a, and finally, the value of temp is assigned to b. This effectively swaps the values of a and b.This way, the values of a and b are successfully swapped using a third variable additionally .
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