x = 0
x = 42
Compilation fails because of an error in line 2 of class Test2.
Compilation fails because of an error in line 3 of class Test1.
Compilation fails because of an error in line 4 of class Test2.
第1题:
有以下源程序: package test; public class ClassA { int x=20; static int y=6; public static void main(String args[]) { ClassB b=new ClassB(); b.go(10); System.out.println("x="+b.x); } } class ClassB { int x; void go(int y) { ClassA a=new ClassA(); x=a.y; } } 上述源程序文件的运行结果为( )。
A.x=10
B.x=20
C.x=6
D.编译不通过
第2题:
package test1; public class Test1 { static int x = 42; } package test2; public class Test2 extends test1.Test1 { public static void main(String[] args) { System.out.println(“x = “ + x); } } What is the result?()
第3题:
现有: class Top { static int X=l; public Top() { x*=3; } } class Middle extends Top { public Middle() {x+=l; } public static void main(String [] args) { Middle m=new Middle(); System.out.println (x); } } 结果是什么?()
第4题:
class TestA { public void start() { System.out.println(”TestA”); } } public class TestB extends TestA { public void start() { System.out.println(”TestB”); } public static void main(String[] args) { ((TestA)new TestB()).start(); } } What is the result?()
第5题:
public class Test { public static void main(String[] args) { int x = 0; assert (x > 0) ? “assertion failed” : “assertion passed”; System.out.println(“Finished”); } } What is the result?()
第6题:
public class Test { private static int[] x; public static void main(String[] args) { System.out.println(x[0]); } } What is the result?()
第7题:
public class Starter extends Thread { private int x= 2; public static void main(String[] args) throws Exception { new Starter().makeItSo(); } public Starter() { x=5; start(); } public void makeItSo() throws Exception { join(); x=x- 1; System.out.println(x); } public void run() { x *= 2; } } What is the output if the main() method is rum?()
第8题:
0
1
2
Compilation fails.
第9题:
x = 0
x = 42
Compilation fails because of an error in line 2 of class Test2.
Compilation fails because of an error in line 3 of class Test1.
Compilation fails because of an error in line 4 of class Test2.
第10题:
1
2
3
编译失败
第11题:
s 14
s 16
s 10
Compilation fails.
An exception is thrown at runtime.
第12题:
2
3
4
编译失败
第13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14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15题:
class Super { public int i = 0; public Super(String text) { i = 1; } } public class Sub extends Super { public Sub(String text) { i = 2; } public static void main(String args[]) { Sub sub = new Sub(“Hello”); System.out.println(sub.i); } } What is the result?()
第16题:
class Top { static int x = 1; public Top(int y) { x *= 3; } } class Middle extends Top { public Middle() { x += 1; } public static void main(String [] args) { Middle m = new Middle(); System.out.println(x); } } 结果为:()
第17题:
现有: class Top { static int x=l; public Top (inty) { x*=3; } } class Middle extends Top { public Middle() {x+=1; ) public static void main (String [] args) { Middle m = new Middle(); System. out .println (x); } } 结果为:()
第18题:
public class Test { public static void main(String[] args) { int x = 0; assert (x > 0): “assertion failed”; System.out.println(“finished”); } } What is the result?()
第19题:
0
null
Compilation fails.
A NullPointerException is thrown at runtime.
An ArrayIndexOutOfBoundsException is thrown at runtime.
第20题:
4
5
8
9
Compilation fails.
An exception is thrown at runtime.
It is impossible to determine for certain.
第21题:
The output is x = 6 y = 0
The output is x = 7 y = 0
The output is x = 6 y = -1
The output is x = 7 y = -1
Compilation will fail.
第22题:
finished
Compilation fails.
An AssertionError is thrown and finished is output.
An AssertionError is thrown with the message “assertion failed”.
An AssertionError is thrown with the message “assertion passed”.
第23题:
1
2
3
编译失败
第24题:
finished
Compilation fails.
An AssertionError is thrown.
An AssertionError is thrown and finished is output.