Szathmáry László honlapja @ DEIK

Nim has both static arrays (like in C) and dynamic arrays (like in Python). This time, let's see the static arrays.

Static arrays are fixed-sized arrays. Their size is decided upon creation and later it cannot be changed. A static array cannot grow or shrink.

static arrays
#include <stdio.h> int main() { int numbers[] = {2, 3, 7, 5}; int n = sizeof(numbers) / sizeof(numbers[0]); printf("n: %d\n", n); // 4 return 0; }	var a: array[3, int] = [5, 7, 9] b = [2, 3, 7, 5] d: array[7, string] echo b.len # 4 d[0] = "hello" echo d[0] # hello

a: we specify the type of the array and we initialize it

b: the type is inferred; the array is initialized

d: the array is declared but not initialized explicitly. It'll be initialized implicitly, and the array will contain 7 empty strings. Later, values can be assigned to the cells of the array.

Since these arrays are var arrays, they are mutable. A let array would be immutable.

Specify the index range

The indexing doesn't have to start with 0. When you create a static array, you can specify the index range:

var
a: array[1..5, int] # filled with 0s

a[1] = 1
a[3] = 1
a[5] = 1

echo a # [1, 0, 1, 0, 1]

#echo a[0] # ERROR: invalid index

𝥶Now, indexing starts with 1 and the highest index is 5.