Example of memory allocation in C.

allocation.c

// Example of memory allocation in C.
// For educational purposes only.
// Author: Vaclav Bohac 


#include <stdio.h>
#include <stdlib.h>


int main( void )
{
	int* number = malloc(sizeof(int));
	*number = 3;
	printf("Number is %d.\n", *number);
	free(number);


	char* foo = malloc(sizeof(char));
	*foo = 'a';
	printf("Foo is %c.\n", *foo);
	free(foo);


	char** bar = malloc(sizeof(char*));
	*bar = "Hello, World!";
	printf("%s\n", *bar);
	free(bar);


	int* array = malloc(4 * sizeof(int));
	for (int i = 0; i < 4; i++) {
		array[i] = i * i;
		printf("%d. %d\n", i + 1, *(array + i));
	}
	free(array);


	char** list = malloc(4 * sizeof(char*));
	list[0] = "Live";
	list[1] = "the Universe";
	list[2] = "and";
	list[3] = "Everything";
	printf("%s, %s %s %s\n", list[0], list[1], list[2], list[3]);
	free(list);	


	struct point {
		int	x, y;
	};
	struct point* p = malloc(sizeof(struct point));
	p->x = 2;
	p->y = 2;
	printf("A (%d, %d)\n", p->x, p->y);
	free(p);

	return 0;
}