public class Alpha{ private static Character() ids; public static void main( String[] args){ ids = new Character[args.length]; for (int i=0; i
第1题:
public class Something {
public static void main(String[] args) {
Other o = new Other();
new Something().addOne(o);
}
public void addOne(final Other o) {
o.i++;
}
}
class Other {
public int i;
}
和上面的很相似,都是关于final 的问题,这有错吗?
正确。在addOne method 中,参数o 被修饰成final。如果在addOne method 里我们修
改了o 的reference
(比如: o = new Other();),那么如同上例这题也是错的。但这里修改的是o 的member vairable
(成员变量),而o 的reference 并没有改变。
第2题:
A.0123 B.0122 C.123 D.234
第3题:
A.Compilationfails.
B.Thecoderunswithnooutput.
C.Anexceptionisthrownatruntime.
D.Thecoderuns,outputingaconcatenatedlistoftheargumentspassedtotheprogram.
第4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5题:
( 30 )在程序的下划线处应填入的选项是
public class Test _________{
public static void main(String args[]){
Test t = new Test();
Thread tt = new Thread(t);
tt.start();
}
public void run(){
for(int i=0;i<5;i++){
system.out.println( " i= " +i);
}
}
}
A ) implements Runnable
B ) extends Thread
C ) implements Thread
D ) extends Runnable
第6题:
下列代码的执行结果是( )。
public class Test{
public int aMethod( ){
static int i=0;
i++;
System.out.println(i):
}
public static void main (String args[]){
Trest test=new Test ( );
test aMethod( ):
}
}
A.编译错误
B.0
C.1
D.运行成功,但不输出
B.
C.
D.
第7题:
以下程序的运行结果为?
class ValHold{
public int i = 10;
}
public class ObParm{
public static void main(String argv[]){
ObParm o = new ObParm();
o.amethod();
}
public void amethod(){
int i = 99;
ValHold v = new ValHold();
v.i=30;
another(v,i);
System.out.print( v.i );
}
public void another(ValHold v, int i){
i=0;
v.i = 20;
ValHold vh = new ValHold();
v = vh;
System.out.print(v.i);
System.out.print(i);
}
}
A.10030
B. 20030
C. 209930
D. 10020
第8题:
下列代码的执行结果是public class Test{ public int aMethod(){ static int i=0; i++; System.out.println(i); } public static void main(String args[]){ Test test= new Test(); test. aMethod(); }}
A.编译错误
B.0
C.1
D.运行成功,但不输出
第9题:
public class Test { public static void add3 (Integer i) { int val = i.intValue(); val += 3; i = new Integer(val); } public static void main(String args[]) { Integer i = new Integer(0); add3(i); System.out.println(i.intValue()); } } What is the result? ()
第10题:
public class test ( public static void main(string args) { int 1= 0; while (i) { if (i==4) { break; } ++i; } } ) What is the value of i at line 10?()