tutorial arrays

Arrays

Ever get tired of writing variable1, variable2, variable3, ... variable100?

Arrays in C have fixed length. This means that once you declare them, you can't change their size.

Arrays are declared more or less like variables; after the name, add brackets with the desired length of the array.

int array[10];      // declare an array with 10 elements

Arrays can also be declared as type*; if the array is assigned at creation, this will be automatically given the appropriate length.

int *array = {1, 2, 3, 4, 5};

NOTE: just declaring the array, and not assigning values creates something called a pointer that is discussed later.

Access arrays using the bracket operator:

int array[10];
array[5] = 42;      // Set the 5th element to 42
int x = array[5];   // Retrieve the 5th element
printf("%d\n", x);

Since C wasn't designed by degenerates, Arrays are indexed starting at 0; therefore, a 10 element array has indices 0,1,2...9 available:

int array[10];
array[0] = 1;       // ok
array[9] = 1;       // all good
array[10] = 1;      // *refuses to compile*

On a related note, C doesn't have strings. Instead, we have char*: arrays of characters.

char *thisIsAString = "This is a string.";
printf("%s\n", thisIsAString);