举一反三
- E类中System.out.println的输出结果是__________、________________。interface Com{int add(int a,int b);}abstract class A{abstract int add(int a,int b);}class B extends A implements Com{public int add(int a,int b){return a+b;}}public class E{public static void main(String args[ ]){B b=new B();Com com=b;System.out.println(com.add(12,6));A a=b;System.out.println(a.add(10,5));}}
- 阅读程序题(给出【代码】注释标注的代码的输出结果)interface Com {int add(int a, int b);public static int get(int n){return n;}public default int see( int n){return n;}public default int look( int n) {return n;}}class A implements Com{public int add( int a, int b) { return a + b;}public int see(int n){ return n + 1;}}public class 习题5_阅读4{public static void main( String args[ ]) {A a = new A();int m = a.add(12,6);int n = Com.get( 12);int t = a.see(6);int q = a.look(6);System.out.printf("%d:%d:%d:%d",m,n, t,q); //【代码】 }}}
- 5.请说出E类中[代码1]，[代码2]的输出结果依次是______ ，______ 。 interface Com { int add(int a,int b); }abstract class A { abstract int add(int a,int b);int g(int a,int b) { return a+b; }}class B extends A implements Com{ public int add(int a,int b) { return a+b; } int g(int a,int b) { return a*b; }}public class E {public static void main(String args[]) { B b = new B(); Com com = b; System.out.println(com.add(10,5)); //[代码1] A a = b; System.out.println(a.g(10,5)); }} //[代码2]
- 下列代码的输出结果是（ ）interface Com{ int M=100; int on();}class A implements Com{ public int on(){ return Com.M; }}public class E{ public static void main(String args[]){ Com com=new A(); int m=com.on(); System.out.println(m); }}
- 给出下列【代码】注释标注的代码的输出结果。abstract class A {abstract int get(int a,int b);}public class E {public static void main(String args[]) {A a=new A() {public int get(int a,int b){return a+b;}};int m = a.get(2,5);a=new A() {public int get(int a,int b){return a*b;}};int n = a.get(2,5);System.out.printf("%d:%d",m,n);//【代码】}}
内容
- 0
下列选项中，（ ）代码替换源文件Com.java中的【代码】不会导致编译错误。public interface com{int M=200;int f();}class ImpCom implements Com{【代码】} A: public int f( ){return 100+M;} B: int f( ){return 100;} C: public double f( ){return 2.6;} D: public abstract int f( );
- 1
程序填空：interface Com{ int M=200; int f(); } class ImpCom implements Com{ ___________________________; } A: public int f(){retrun 100+M;} B: int f() {return 100;} C: public double f(){return 2.6;} D: public abstract inf f();
- 2
public class test1 { public static int add(int a, int b) { return a+b; } public static double add(double a, double b) { return a+b; } ________________ ___________________ { ________________ ___________________ } public static void main(String[] args) { System.out.println("调用add方法:"+add(2.1,3.4,4.5)); } }
- 3
以下程序运行结果是 public class Test { public static void main(String[] args) { int a=1，b[]={2}; add(a); add(b); System.out.println(a+","+b[0]); } static int add(int x){ x++; return x; } static void add(int[] x){ x[0]++; } }
- 4
下列代码能否正常运行，如果能够正常运行，输出结果是什么？ public class TestClass { public static void main(String[] args) { int num1=5; int num2=5; class InnerClass{ public int add(){ return num1+num2; } }; InnerClass in=new InnerClass(); System.out.println(in.add()); } }