Useful ammo for any pass by value debates (Java, Python, etc)

pass_by_value_demo.c

#include <stdio.h>
#include <malloc.h>

void value_swap(int, int);
void reference_swap(int*, int*);
void memory_swap(int*, int*);

int main(int argc, char **argv)
{
	int* a = malloc(sizeof(int));
	int* b = malloc(sizeof(int));

	*a = 0;
	*b = 1;
	
	printf("Initial values\n");
	printf("a: %d b: %d\n", *a, *b);
	value_swap(*a, *b);
	printf("After value swap\n");
	printf("a: %d b: %d\n", *a, *b);
	reference_swap(a, b);
	printf("After reference swap\n");
	printf("a: %d b: %d\n", *a, *b);
	memory_swap(a, b);
	printf("After memory swap\n");
	printf("a: %d b: %d\n", *a, *b);

	return 0;
}

/* Pass by value */
void value_swap(int a, int b)
{
	int* temp;
	*temp = a;
	a = b;
	b = *temp;
	printf("In value swap\n");
	printf("a: %d b: %d\n", a, b);
}

/* Reference is also passed by value */
void reference_swap(int* a, int* b)
{
	int* temp;
	temp = a;
	a = b;
	b = temp;
	printf("In reference swap\n");
	printf("a: %d b: %d\n", *a, *b);
}

/* However, with a reference we can change the memory it points at */
void memory_swap(int* a, int* b)
{
	int* temp;
	*temp = *a;
	*a = *b;
	*b = *temp;
	printf("In memory swap\n");
	printf("a: %d b: %d\n", *a, *b);
}