How to update existing object value?

Developers Programs & Applications
1

I’m trying to update value but give this error.
expected mutable assignment target

 type Invoice = {
   invoice_no:Nat;
 };
var InvoiceObj : Invoice = {
   invoice_no = 0;
};
InvoiceObj.invoice_no:=10;

How to update this value?

2

Change the type declaration to:

type Invoice = {
  var invoice_no:Nat;
 };
3 
InvoiceObj := { invoice_no = 10 };

Or change invoice_no to var invoice_no like @v1ctor suggested.

1 Like
4

I tried but it’s give me this error

type Invoice = {
  var invoice_no:Nat;
 };

var InvoiceObj : Invoice = {
   invoice_no = 0; // Error expected mutable 'var' field total of type  Nat but found immutable field (insert 'var'?)
};
5

If there’s any mutable field, declared with “var”, you have to repeat that when creating a new object:

type SomeType = {
 var field: Nat;
};
var obj: SomeType = {
   var field = 1234;
};
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