joegasewicz

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

int main()
{
    int myInt;
    signed int mySignedInt;
    unsigned int myUnsignedInt;

    short myShort;

joegasewicz

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

int main()
{
    /* ====================================================================== */
    /*  Double Pointers (Pointer to a Pointer) */
    /* ====================================================================== */
    // 2 levels of indirection
    int **dblPtr;

joegasewicz

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

int main()
{
      /* ====================================================================== */
      /*  Dynamic Memory Allocation */
      /* ====================================================================== */
      char *str = NULL;

joegasewicz

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


void square_num(int *num);

int main()
{
    /* ====================================================================== */
    /* Pass By Reference */

joegasewicz

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

int calc_len_str(const char *str);

int main()
{
    char str[] = "How are you today!";
    int result = calc_len_str(str);
    printf("result 1 = %d\n", result);

joegasewicz

int main()
{
    char string1[] = "A string to be copied.";
    char string2[50];
    
    copyStrong1(string2, string1); 
    return 0;
}

joegasewicz

int main() 
{

/* ====================================================================== */
    /* Pointer Arithmetic */
    /* ====================================================================== */
    /*
        int urn[3];
        int *ptr1, *ptr2

joegasewicz

    /* ====================================================================== */
    /* Pointers to Arrays */
    /* ====================================================================== */

    // point to first item in an array
    char arr[] = {'a', 'b', 'c'};
    // apply the address operator to the first element in the array
    char *arrPtr = &arr[0]; // without address operator you would get a value
    // C compiler treats the array name (arr) without subscript ([])
    // as a pointer to the array.

joegasewicz

   /* ====================================================================== */
    /* Void Pointers*/
    /* ====================================================================== */

    // void* absence of a type means you are able to store any type
    // - Often used as a return type or a parameter type of functions
    // - You must cast it to a type when you dereference it
    int i = 10;
    float f = 2.34;
    char ch = 'k';

joegasewicz

    

// * - indirection operator
    int *pNumber = NULL, myNum = 1;
    char *my_str = "hello";
    long num1 = 0L, num2 = 0L, *pNum = NULL;

    if (pNumber == NULL)
        printf("pNumber is currently NULL\n");
    pNumber = &myNum;