# Oh shit C!
Some C examples for quick reference.

## Strings
```c
// remember the null terminator!
char greet[] = {'H', 'e', 'l', 'l', 'o', '\0'};

int len = sizeof(greet) / sizeof(char);
for (i = 0; i < len; i++) {
    printf("%c", greet[i]);
}
```

## Arrays
```c
// pointer to array of names
char *names[] = {
  "Foobar", "BarBaz"
};
```

## Pointers

### Address/Reference operator
```c
int age = 35;
int *age_ptr = &age;
```
### Dereferencing
```c
int age = 35;
int *age_ptr = &age;

// deference example
assert(++*age_ptr == 36)
```
### Pointer to Pointer
```c
int age = 35;
int *age_ptr = &age;
int **age_ptr_ptr = &age_ptr;
// and so on

// needs to include <assert.h>
assert(**age_ptr_ptr, *age_ptr);
```

### Pointer to Array
```c
int ages[3] = {10, 20, 30};
int *ages_ptr = ages;

for (int i = 0; i < 3; i++) {
    assert(*(ages_ptr + i) == ages[i]);
}
```
### Pointer to Function
```c
int add(int a, int b)
{
  return a + b;
}

int (*plus)(int, int);
plus = add;

assert(plus(2, 2) == add(2, 2));
```

### Pointer to Structures
```c
struct Point
{
    int x;
    int y;
};

// need to include <stdlib.h> for malloc
struct Point *point = malloc(sizeof(struct Point));
point->x = 5;
point->y = 5;

assert(point->x == 5);
assert(point->y == 5);

// make sure to free it up!
free(point);
```