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http://202.201.112.11/jpk/apply/teacher/preface/53/test123/test3/exam.htm
1.½Ó¿ÚÖз½·¨µÄÇ°ÃæÓÐÄÄЩÐÞÊηû
·ÃÎÊȨÏÞ ·µ»ØÖµÀàÐÍ ÊÇ·ñ¾²Ì¬ ÊÇ·ñ³éÏó
2.ÒÔÏÂÄĸöÎªÕæ
Interger a = new Interger(9);
Interger b = new Interger(9);
Long c = New Long(9)
-----
A. a==b
B. b==c
C. a.equals(b)
D. b.equals(new Interger(9))
cd
3.ÒÔÏÂÄÄÁ½¸ö·½·¨¿ÉÒÔ¼Óµ½threeÖÐ
class one{
public one foo(){return this;}
}
class two extends one{
public one foo(){return this;}
}
class three extends two{
//²åÈëµ½Õâ
}
---
A. public void foo(){}
B. public int foo(){return 1;}
C. public one foo(){return this;}
d. public two foo(){return this;}
e. public object foo(){return this;}
cd
4.ÒÔÏÂÄÄЩΪtrue
class a{}
class b extends a{}
class c extends a{}
a p0=new a();
b p1=new b();
c p2=new c();
a p3=new b();
a p4=new c();
----
A. p1 = (b)p2
B. p3 = (a)p4
C. p3 = (b)p4
d. p0 = (a)p1
bcd
5. ÒÔÏÂÓÐÎÞÎÊÌâ
abstract class a{
public void fo(){ system.out.println("a");}
}
ÎÞ ³éÏóÀà¿ÉÒÔÓзdzéÏó·½·¨
6. ÒÔÏÂÓÐÎÞÎÊÌâ
abstract class b{
static void f1(){ system.out.println("f1");}
public static void main(String[] args){
b b1=new b(); //³éÏóÀ಻ÄÜÓÐʵÀý
b1.f1();
}
}
7. ÒÔÏ´úÂëÔËÐнá¹ûÊÇ
try{
//´ËÐлáÅ׳öNullPointedException
}
catch(NullPointedExecption e){
System.out.print("1")
}
catch(RuntimeExection e){
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