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Erase

procedure Erase;

Example​

procedure ScriptEvent(var Value: variant);
var
  Values: TJSONArray;
begin
  Values := TJSONArray.Create;
  try
    Values.AddString('old');
    Values.Erase;
    Values.AddString('new');
    Value := Values.AsString;
  finally
    Values.Free;
  end;
end;

Usage​

Erase frees every owned array item while retaining the same always-non-null array object for reuse.

Additional Technical Info​

Erase calls fItems.Clear. The owning list immediately frees every child recursively and sets Count to zero. The TJSONArray object itself remains usable, but all previously returned item/descendant references become invalid.

The method does not change Name or the inherited private null-storage bit. The stored bit is not a public array state: TJSONText.IsNull always returns false and AsString serializes an erased array as [], even if a caller previously assigned IsNull=True. No null reset is required before reuse. The script NotNull property is misbound and also reads false, so use not Values.IsNull when a positive predicate is required.

Inherited virtual Clear dispatches to the array override, which simply calls this same Erase implementation rather than the ancestor behavior that marks a scalar null. Clear and Erase are therefore equivalent for arrays in this product version.

External references

Created 2026-07-20