#include <stdio.h>

union Test
{
    int i;
    char c;
};

int main()
{
    Test ts;
    ts.i = 1;
    printf("%d", (int)ts.c);
    
    return 0;
}

#include <stdio.h>

int main()
{
    int i;
    int num = 0x12345678;
    char* ptr = (char*) &num;
    for (i = 0 ; i < 4; i++)
    {
        printf("%p\t%x\n", ptr, *ptr);
        ptr++;
    }
    
    return 0;
}

#include <stdio.h>

int main(void)
{
        char     c;
        int      i;

        i = -300;
        c = i;
        printf("%d\n", (int)c);
        c = i && 0xff;
        printf("%d\n", (int)c);
        c = *(char *)&i;
        printf("%d\n", (int)c);
        return 0;
}

int b = 0x30313233; // 0x30 is ascii for '0', and so on
char a = (char)b; // cast from int to char: get the "last" byte 0x33
                  // i.e. b & 0xff
char a = *(char*)&b; // get the byte pointed by the "&b"
                     // cast to make "&b" a char pointer
bin-endian:
base_address + 3: |0x33|                   
base_address + 2: |0x32|                   
base_address + 1: |0x31|                   
base_address + 0: |0x30| <-- &b point here

little-endian:
base_address + 3: |0x30|                   
base_address + 2: |0x31|                   
base_address + 1: |0x32|                   
base_address + 0: |0x33| <-- &b point here

default, &b is a pointer of int and 4 bytes will be interpreted;
by casting &b into a pointer of char, only 1 byte is interpreted.

#include <stdio.h>

typedef unsigned char BYTE;

void print_object(const BYTE *base, int size)
{
        printf("object is at %p\n", base);
        printf("                     address   content   ascii\n");
        while(size > 0)
        {
                --size;
                printf("base_address + %d: %p |  0x%02X  | %c\n",
                        size,
                        base + size,
                        *