関連ワード:  java check if object is empty    java check if object is empty or null    how to check if object is empty javascript    how to check if object is empty    how to check if object is empty typescript    how to check if object is empty c#    how to check if object is empty or not    how to check if object is empty or not in javascript    how to check if object is empty python    how to check if object is empty in angular