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Count

property Count: Integer read;

Example​

procedure ScriptEvent(var Value: variant);
var
  Values: TJSONArray;
  I: Integer;
begin
  Values := TJSONArray.Create;
  try
    Values.LoadFromString('["A","B"]');
    Value := '';
    for I := 0 to Values.Count - 1 do
      Value := Value + Values[I].AsString;
  finally
    Values.Free;
  end;
end;

Usage​

Count returns the current number of owned child nodes in the JSON array.

Additional Technical Info​

Count returns the backing object list's current item count. It includes every node type, including real JSON null values and null-marked string nodes. It does not count descendants inside nested arrays or objects.

Valid Items indexes are zero through Count - 1. With Count=0, a Pascal for I := 0 to Count - 1 loop performs no iterations. Indexed access outside the range raises.

Addition increases the value; delete decreases it; erase sets it to zero; successful loading replaces it with the parsed array count. References and indexes can be invalidated by any of those mutations, so do not cache them across changes. The property is not a concurrency snapshot and the class is not thread-safe.

Count=0 means that the array owns no child nodes. The container itself still reads IsNull=False and serializes as [], even if a script previously assigned IsNull=True; TJSONText fixes the getter to false. Do not use script NotNull as the inverse because the runtime importer misbinds it to the same false-valued IsNull helper.

External references

Created 2026-07-20