I suspect this will turn up in a few search results too.
In one of my digital classes we are reviewing C programming practices, and one of the hard concepts to get is pointers. I thought I would sit down and play with them for a while to figure it all out.
This is what I came up with:
Sample program:
//========================================================
//== The purpose of this C program is to simplify the
//== mystery behind pointers with a minimal amount of
//== other crazy stuff going on at the same time.
//==
//== Compiled under gcc on linux, ver. 4.7.2
//== Sept. 20, 2013
//========================================================
#include <stdio.h>
#include <stdlib.h>
char msg[] = "I like cheese"; //declared here to give global scope
int main ()
{
char msg2[] = "CHEDDAR ROCKS!"; //declared here to put it on the stack.
// -= only visible in the main =-
char * string = msg; //create variable of type address to hold base address of msg
char * string2 = msg2;
printf("\n\nA string stored on the activation record: \n");
printf("%s at address %p, the first character is %c \n", msg, msg, *msg);
//above code uses format specifiers for showing a string, an address
// and the contents at the first memory location for 'msg'.
while (*string != '\0') //loop increments until the examined memory address contains
//null character (\0)
{
printf("address: %p, Character %c \n",string, *string); //shows address
string++; //and its contents
}
//The following while loop is identical to the one above, except the string is located
//in a different area of the memory
printf("\nA string stored on the stack: \n");
while (*string2 != '\0')
{
printf("address: %p, Character %c \n",string2, *string2);
string2++;
}
return (0);
}
Let's look at the output:
So this might look like a lot of junk, but it's pretty interesting to see how stuff is stored in memory on your computer. This same code could be made to work on many other devices too.
Hopefully this finds its way to someone trying to understand the topic. I did this to help myself, so maybe it can help you!
Hopefully I don't geek myself up too much for my social media class :)
