Given the command line java Pass2 and: public class Pass2 { public void main(String [] args) { int x=6; Pass2 p = new Pass2(); p.doStuff(x); System.out.print(” main x = “+ x); } void doStuff(int x) { System.out.print(” doStuffx = “+ x++); } } What is the result?()
第1题:
interface A{
int x = 0;
}
class B{
int x =1;
}
class C extends B implements A {
public void pX(){
System.out.println(x);
}
public static void main(String[] args) {
new C().pX();
}
}
错误。在编译时会发生错误(错误描述不同的JVM 有不同的信息,意思就是未明确的
x 调用,两个x 都匹配(就象在同时import java.util 和java.sql 两个包时直接声明Date 一样)。
对于父类的变量,可以用super.x 来明确,而接口的属性默认隐含为 public static final.所以可
以通过A.x 来明确。
第2题:
下面程序段的输出结果为 package test; public class A { int x=20; static int y=6; public static void main(String args[]) { Class B b=new Class B(); b.go(10); System.out.println(”x=”+b.x); } } class Class B { int x; void go(int y) { ClassA a=new ClassA(); x=a.y; } }
A.x=10
B.x=20
C.x=6
D.编译不通过
第3题:
现有: class Passer f static final int X=5; public static void main (String [] args) { new Passer().go (x); System. out .print (x); } void go (int x) { System. out .print(x++); } 结果是什么?()
第4题:
interface DeclareStuff{ public static final int EASY = 3; void doStuff(int t); } public class TestDeclare implements DeclareStuff { public static void main(String [] args) { int x=5; new TestDeclare().doStuff(++x); } void doStuff(int s) { s += EASY + ++s; System.out.println(”s “ + s); } } What is the result?()
第5题:
public class Pass { public static void main(String [1 args) { int x 5; Pass p = new Pass(); p.doStuff(x); System.out.print(” main x = “+ x); } void doStuff(int x) { System.out.print(” doStuff x = “+ x++); } } What is the result?()
第6题:
public class Yippee { public static void main(String [] args) { for(int x = 1; x < args.length; x++) { System.out.print(args[x] +“ “); } } } and two separate command line invocations: java Yippee java Yippee 1234 What is the result?()
第7题:
class Beverage { Beverage() { System.out.print("beverage "); } } class Beer extends Beverage { public static void main(String [] args) { Beer b = new Beer(14); } public int Beer(int x) { this(); System.out.print("beer1 "); } public Beer() { System.out.print("beer2 "); } } 结果是什么?()
第8题:
Compilation fails.
An exception is thrown at runtime.
doStuffx = 6 main x = 6
doStuffx = 5 main x = 5
doStuffx = 5 main x = 6
doStuffx = 6 main x = 5
第9题:
Compilation fails.
An exception is thrown at runtime.
doStuffx=6 main x=6
doStuffx=6 mainx =7
doStuffx=7 mainx =6
doStuffx=7 mainx =7
第10题:
55
56
65
66
第11题:
23
21
22
编译错误
第12题:
main
编译失败
代码运行,但没有输出
main java.lang.RuntimeException: exception
第13题:
下面程序段的输出结果为( )。 package test; public class ClassA { int x=20: static int y=6; public static void main(String args[]) { ClassB b=new ClassB; go(10); System.out.println("x="+b.x); } } class ClassB { int X; void go(int y) { ClassA a=new ClassA; x=a.Y ; } }
A.x=10
B.x=20
C.x=6
D.编译不通过
第14题:
以下程序调试结果为:
public class Test {
int m=5;
public void some(int x) {
m=x;
}
public static void main(String args []) {
new Demo().some(7);
}
}
class Demo extends Test {
int m=8;
public void some(int x) {
super.some(x);
System.out.println(m);
}
}
A.5
B.8
C.7
D.无任何输出
E.编译错误
第15题:
程序: class TestReference{ public static void main(String[] args){ int x=2; TestReference tr = new TestReference(); System.out.print(x); tr.change(x); System.out.print(x); } public void change(int num){ num = num + 1; } } 程序运行后的输出是哪项?()
第16题:
class ThreadExcept implements Runnable { public void run() { throw new RuntimeException("exception "); } public static void main(String [] args) { new Thread(new ThreadExcept()).start(); try { int x = Integer.parseInt(args[0]); Thread.sleep(x); System.out.print("main "); } catch (Exception e) { } } } 和命令行: java ThreadExcept 1000 哪一个是结果?()
第17题:
class Beta { public static void main(String [] args) { Integer x = new Integer(6) * 7; if (x != 42) { System.out.print("42 "); } else if (x.equals(42)) { System.out.print("dot = "); } else { System.out.print("done"); } } } 结果为:()
第18题:
class Passer { static final int x = 5; public static void main(String [] args) { new Passer().go(x); System.out.print(x); } void go(int x) { System.out.print(++x); } } 结果是什么?()
第19题:
No output is produced. 123
No output is produced. 234
No output is produced. 1234
An exception is thrown at runtime. 123
An exception is thrown at runtime. 234
An exception is thrown at rijntime. 1234
第20题:
Compilation fails.
An exception is thrown at runtime.
doStuffx = 6 main x = 6
doStuffx = 6 main x = 7
doStuffx = 7 main x = 6
doStuffx = 7 main x = 7
第21题:
doStuff x = 6 main x = 6
Compilation fails.
doStuff x = 6 main x = 7
An exception is thrown at runtime.
doStuff x = 7 main x = 6
doStuff x = 7 main x = 7
第22题:
s 14
s 16
s 10
Compilation fails.
An exception is thrown at runtime.
第23题:
Compilation fails.
An exception is thrown at runtime.
doStuff x=6 main x=6
doStuff x=5 main x=5
doStuff x=5 main x=6
doStuff x=6 main x=5