Creating an empty array of Strings of size x that can be updated

Question

I'm trying to create an array of strings so that I can modify the contents of the strings depending on the input parameter of a function. I've only started to use OCaml recently so I may be missing something simple here. Currently I have:

  let myArray = Array.make x "" in
    for i = 0 to Array.length myArray do
    myArray[i] = "SOME STRING HERE";
  done;

However when doing this, I get the following error when performing ocamlbuild

Error: This expression has type string array This is not a function; it cannot be applied.

Please don't keep changing your code. It makes the previous answers incorrect. — Jeffrey Scofield, Mar 19 '19 at 18:23
Please test your code to make sure it actually demonstrates the problem and does not contain an error on every other token. See how to make a [mcve] for more. — glennsl, Mar 19 '19 at 18:30
You have edited your code so that it now works OK, but this makes your question incoherent. Please leave your original question intact for later readers of StackOverflow. — Jeffrey Scofield, Mar 19 '19 at 18:31
@JeffreyScofield I have rollbacked to revision 1. You could have done the same BTW. — Jean-François Fabre, Mar 20 '19 at 20:06

score 1 · Accepted Answer · answered Mar 19 '19 at 18:20

1

Assignment to an array looks like this in OCaml:

myArray.(i) <- "SOME STRING HERE"

As an additional comment, your loop is accessing past the end of the array. The last element of an array is Array.length array - 1.

answered Mar 19 '19 at 18:20

Jeffrey Scofield

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Sorry, made a mistake with that. However that did not fix the problem as per my edit – NiallMitch14 Mar 19 '19 at 18:24
You are still using `[]` for indexing. Indexing of arrays uses `.()`. – Jeffrey Scofield Mar 19 '19 at 18:28
Sorry forgot to change that in the question. Error still applies – NiallMitch14 Mar 19 '19 at 18:30
Syntax wise yes, but it's still giving the error This expression has type string but an expression was expected of type int – NiallMitch14 Mar 19 '19 at 18:31
If I copy/paste your code, it works for me. I tried it twice. Furthermore I see no problems with it :-) – Jeffrey Scofield Mar 19 '19 at 18:32
Is there a problem when trying to update the values of an array from within a function then :S – NiallMitch14 Mar 19 '19 at 18:34
Your original question has been answered. If you're still having problems you should put together a new question. No, there is no problem updating arrays. They are mutable. – Jeffrey Scofield Mar 19 '19 at 18:36
Apologies, I found where the problem lies now. It wasn't to do with the array, something else is causing it – NiallMitch14 Mar 19 '19 at 18:37

Creating an empty array of Strings of size x that can be updated

1 Answers1