Combine
procedure Combine(const aSource: TJSONArray);
Example
procedure ScriptEvent(var Value: variant);
var
Left, Right: TJSONArray;
begin
Left := TJSONArray.Create;
Right := TJSONArray.Create;
try
Left.AddString('A');
Right.AddString('B');
Right.AddString('C');
Left.Combine(Right);
Value := Left.AsString; // ["A","B","C"]
finally
Right.Free;
Left.Free;
end;
end;
Usage
Combine appends deep clones of every source item without transferring or clearing either array.
Additional Technical Info
Combine iterates over the source items in order, calls Clone on each and appends the clones directly to the receiver's owning list. Existing receiver items remain first. The source and its child objects remain unchanged and independently owned.
Combining an array with itself is supported by the loop mechanics: the final source index is fixed when the loop begins, so one clone of each original item is appended rather than an endless loop. Large/nested sources are fully duplicated in memory. Passing nil fails when the method reads its count.
The implementation bypasses the normal protected Add method and therefore does not clear the inherited private null-storage bit. This difference is behaviourally inert for arrays: TJSONText.IsNull always reads false, and AsString serializes every appended item even after a caller assigned IsNull=True. The script NotNull property is also misbound to the false-valued IsNull helper, so use not Left.IsNull when a positive predicate is needed.
The receiver owns all appended clones. References obtained from the source do not point at the clones; obtain new references through receiver Items if needed.
External references
Created 2026-07-20