CODEWITHSUNDEEP
f#
misaochan
misaochan

Reputation: 890

Accessing element from reference array in F#

Was experimenting with arrays and references - my intent is to create a reference to an array and then use that reference inside a closure to access a certain element of the array. FSI attempt:

> let dk2 = Array.create 5 0
let dk2ref = ref dk2;;

val dk2 : int [] = [|0; 0; 0; 0; 0|]
val dk2ref : int [] ref = {contents = [|0; 0; 0; 0; 0|];}

> !dk2ref.[1]

stdin(3,2): error FS0039: The field, constructor or member 'Item' is not defined

Is there a direct way to access the element of a referenced array? (In this case, the 2nd element of dk2ref)?

Upvotes: 3

Views: 603

Answers (1)

pad
pad

Reputation: 41290

I'm not sure why you need a reference array.

Looking up the operator precedence table, . operator has higher precedence than ! operator. So your example is parsed as !(dk2ref.[1]) which causes the error because 'a ref doesn't implement indexed properties.

You just need to add parentheses at the right places: 

> (!dk2ref).[1]
val it : int = 0

Upvotes: 6

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