swap two var 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>
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 a = 10;
6  	int b = 5;
7
8  	//swap start
9  	a = a + b; //a = 10 + 5 = 15
10    b = a - b; //b = 15 - 5 = 5
11    a = a - b; //a = 15 - 5 = 10
12
13  	printf("a = %d / b = %d\n", a, b);
14  	//a = 5 / b = 10
15  	return 0;
16}
17
18
19/*You can create a function*/
20
21void swap(int *a, int *b)
22{
23  	*a = *a + *b; //a = 10 + 5 = 15
24    *b = *a - *b; //b = 15 - 5 = 5
25    *a = *a - *b; //a = 15 - 5 = 10
26}
27
28int main()
29{
30	int a = 10;
31  	int b = 5;
32
33  	//call with adress of the var
34	swap(&a, &b);  
35  	printf("a = %d / b = %d\n", a, b);
36  	//a = 5 / b = 10
37  	return 0;
38}