関連ワード:  is boolean a data type in javascript    is boolean a data type in java    is bool a data type in java    is boolean a primitive data type in java    is boolean a primitive data type in javascript    is boolean a valid data type in java    boolean is a non primitive data type in java    a boolean is not a valid data type in java    what is a boolean data type in java and how is it used    what is the default value of a boolean data type in java