A.get B.let C.set D.is
A.public class B inherit A B.public class B :: A C.public class B : A D.public class B from A
A.允許有多個(gè)相同名稱(chēng)的構(gòu)造函數(shù) B.允許有多個(gè)不相同名稱(chēng)的構(gòu)造函數(shù) C.至少要有一個(gè)構(gòu)造函數(shù) D.只能有一個(gè)構(gòu)造函數(shù)