swap two numbers in c

1#include <stdio.h>
2int main() {
3    double a, b;
4    printf("Enter a: ");
5    scanf("%lf", &a);
6    printf("Enter b: ");
7    scanf("%lf", &b);
8
9    // Swapping
10
11    // a = (initial_a - initial_b)
12    a = a - b;   
13  
14    // b = (initial_a - initial_b) + initial_b = initial_a
15    b = a + b;
16
17    // a = initial_a - (initial_a - initial_b) = initial_b
18    a = b - a;
19
20    printf("After swapping, a = %.2lf\n", a);
21    printf("After swapping, b = %.2lf", b);
22    return 0;
23}
24

1#include <stdio.h>
2 
3void swap(int*, int*);
4 
5int main()
6{
7   int x, y;
8 
9   printf("Enter the value of x and y\n");
10   scanf("%d%d",&x,&y);
11 
12   printf("Before Swapping\nx = %d\ny = %d\n", x, y);
13 
14   swap(&x, &y); 
15 
16   printf("After Swapping\nx = %d\ny = %d\n", x, y);
17 
18   return 0;
19}
20 
21void swap(int *a, int *b)
22{
23   int temp;
24 
25   temp = *b;
26   *b = *a;
27   *a = temp;   
28}
29 

1#include <stdio.h>
2int main()
3{
4    int a, b, temp;
5    printf("enter the values of a and b: \n");
6    scanf("%d%d", &a, &b );
7    printf("current values are:\n a=%d\n b=%d\n", a, b);
8    temp=a;
9    a=b;
10    b=temp;
11    printf("After swapping:\n a=%d\n b=%d\n", a, b);
12}

1#include <stdio.h>
2#include <stdlib.h>
3
4int main()
5{
6  	//initialize variables
7	int num1 = 10;
8	int num2 = 9;
9  	int tmp;
10  	
11  	//create the variables needed to store the address of the variables
12  	//that we want to swap values
13  	int *p_num1 = &num1;
14  	int *p_num2 = &num2;
15  
16  	//print what the values are before the swap
17  	printf("num1: %i\n", num1);
18    printf("num2: %i\n", num2);
19  
20  	//store one of the variables in tmp so we can access it later
21  	//gives the value we stored in another variable the new value
22  	//give the other variable the value of tmp
23  	tmp = num1;
24  	*p_num1 = num2;
25  	*p_num2 = tmp;
26
27  	//print the values after swap has occured
28   	printf("num1: %i\n", num1);
29    printf("num2: %i\n", num2);
30  	
31	return 0;
32}
33

1#include <stdio.h>
2
3int main()
4{
5    int x = 20, y = 30, temp;
6    temp = x;
7    x = y;
8    y = temp;
9    printf("X = %d and Y = %d", x, y);
10    
11    return 0;
12}

1#include<stdio.h>
2
3void swapping(int, int);  //function declaration
4int main()
5{
6    int a, b;
7
8    printf("Enter values for a and b respectively: \n");
9    scanf("%d %d",&a,&b);
10
11    printf("The values of a and b BEFORE swapping are a = %d & b = %d \n", a, b);
12
13    swapping(a, b);      //function call
14    return 0;
15}
16
17void swapping(int x, int y)   //function definition
18{
19    int third;
20    third = x;
21    x    = y;
22    y    = third;
23
24    printf("The values of a and b AFTER swapping are a = %d & b = %d \n", x, y);
25}