classSuper{publicinti=0;publicSuper(Stringtext){i=1;}}publicclassSubextendsSuper{publicSub(Stringtext){i=2;}publicstaticvoidmain(Stringargs[]){Subsub=newSub(Hello”);System.out.println(sub.i);}}Whatistheresult?()
A.0
B.1
C.2
D.Compilationfails.
第1题:
classSuper{publicintgetLenght(){return4;}}publicclassSubextendsSuper{publiclonggetLenght(){return5;}publicstaticvoidmain(String[]args){Supersooper=newSuper();Subsub=newSub();System.out.println(sooper.getLenght()+“,”+sub.getLenght());}}Whatistheoutput?()
A.4,4
B.4,5
C.5,4
D.5,5
E.Compilationfails.
第2题:
A.publicvoidgetNum(){}
B.publicvoidgetNum(doubled){}
C.publicfloatgetNum(){return4.0f;}
D.publicdoublegetNum(floatd){return4.0d;}
第3题:
对于下列代码,下列哪个叙述是正确的? class A { public int i=0; A(int m) { i = 1; } } public class B extends A { B(int m) { i = 2; } public static void main(String args[]){ B b = new B(100); System.out.println(b.i); //【代码】 } }
A.程序提示编译错误。
B.编译无错误,【代码】输出结果是0。
C.编译无错误,【代码】输出结果是1。
D.编译无错误,【代码】输出结果是2。
第4题:
classSuper{publicIntegergetLenght(){returnnewInteger(4);}}publicclassSubextendsSuper{publicLongGetLenght(){returnnewLong(5);}publicstaticvoidmain(String[]args){Supersooper=newSuper();Subsub=newSub();System.out.println(sooper.getLenght().toString()+,”+sub.getLenght().toString());}}Whatistheoutput?()
A.4,4
B.4,5
C.5,4
D.5,5
E.Compilationfails.
第5题:
A.PublicfloatgetNum(){return4.0f;}
B.PublicvoidgetNum(){}
C.PublicvoidgetNum(doubled){}
D.PublicdoublegetNum(floatd){retrun4.0f;}