Head First C

gcc read.c -o read

Address of the variable - & Read contents - *

void change_location(int* x, int* y) {
  *x = *x + 1
  *y = *y + 1
}
ship_x = 0;
ship_y = 0;
change_location(&ship_x, &ship_y);

Passing a string:

void fortune_cookie(char msg[]) {}
fortune_cookie("OHAI");

Array Variables:

char s[] = "How big is it?";
char *t = s;

sizeof(a pointer) returns the value 4 or 8, depends on whether 32bit or 64bit

Pointer Arithmetic:

printf("3rd order: %i drinks\n", drinks[2]);
printf("3rd order: %i drinks\n", *(drinks + 2));

You can also do the following:

int doses[] = {1, 3, 2, 1000};
printf("Issue dose %i", 3[doses]);

Declare a variable with a size:

char name[40];

If you run over this size, then a buffer overflow will occur.

You can use fgets as well as scanf, which takes the pointer, does sizing and stdin as a param:

fgets(food, sizeof(food), stdin);

String literals can NEVER be updated: char *cards = "JQK"; but you can if you update it: char cards[] = "JQK";

n.b. In the above we don't specify a size because it is immediately assigned to a string variable.

It's better to define a string literal as a constants: const char *s = "some string";

2.5 String Thory

Create an array of arrays:

char tracks[][80] = { 'a', 'b', 'c' }

C Standard Library has a bunch of useful code:

String functions:

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