Copying an array to another array

July 5, 2022

Suppose if I have the following array:

(def my-array @[1 2 3 4])

I tried doing:

(array/copy my-array my-array-copy)

but I get an error:

compile error: unknown symbol array/copy

>Solution :

You can make a shallow copy:

(def my-array @[1 2 3 4])
(def my-array-copy my-array)

but when you use (set()) with my-array, it will be reflected in my-array-copy:

# 3 -> 69
(set (my-array 2) 69)
my-array-copy # Output: @[1 2 69 4])

If you don’t want any changes in my-array to be reflected in my-array-copy then
use a while or each loop to copy the elements to the new array:

(def my-array @[1 2 3 4])
(def my-array-copy (array/new (length my-array)))

(var counter 0)
(while (< counter (length my-array))
    (put my-array-copy counter (get my-array counter))
    (++ counter))

# If you dislike readability and love hunting for missing brackets
(each number my-array (put my-array-copy counter 
                      (get my-array counter))(++ counter))

(set (my-array 2) 69)
my-array # Output: @[1 2 69 4])
my-array-copy # Output: @[1 2 3 4])