An array is a fixed length set of elements. There are two ways to create an array: either by specifing each element, semicolon separated, between
|], or by repeting an element a fixed number of times.
let array1 = [|1; 2; 3; 4|];; let array2 = Array.make 3 0;; (* [|0; 0; 0|] *)
You can get the length of an array using the
let array1 = [|1; 2; 3; 4|];; let len = Array.length array1;; (* len = 4 *)
You can get elements from an array using its index. The first element’s index is
0, and the last one’s index is
n-1, for an array of length
let array1 = [|1; 2; 3; 4|] in print_int array1.(2);; (* 3 *)
Using a for loop, you can iterate elements of an array like in this example:
let array1 = [|1; 2; 3; 4|] in let len = Array.length array1 in for k = 0 to len-1 do print_int array1.(k) done;;
In this example,
k will be incremented from
3), and for each value of
k, the element with the index
k will be printed. That way, we can print all elements of an array.
You can also set an element to a new value with its index using an arrow:
let array1 = [|1; 2; 3; 4|] in let len = Array.length array1 in for k = 0 to len-1 do array1.(k) <- 2 * array1.(k) done;; (* array1 = [|2; 4; 6; 8|] *)
In this example, each value of the array is replaced by 2 times the original value.