関連ワード:  typescript check object is null or undefined    javascript check object is null or undefined    typescript check object is not null or undefined    typescript check if object is empty or undefined    javascript check object is not null or undefined    javascript check if object is empty or undefined    javascript check if object property is null or undefined    javascript check if object is empty or null or undefined    typescript check if null or undefined    typescript check if value is object  
結果 : typescript check object is null or undefined