Compilation fails.
An exception is thrown at runtime.
The attribute id in the Item object remains unchanged.
The attribute id in the Item object is modified to the new value.
A new Item object is created with the preferred value in the id attribute.
第1题:
publicclassItemTest{privatefinalmtid;publicItemTest(intid){this.id=id;}publicvoidupdateId(intnewId){id=newId;}publicstaticvoidmain(String[]args){ItemTestfa=newItemTest(42);fa.updateId(69);System.out.println(fa.id);}}Whatistheresult?()
A.Compilationfails.
B.Anexceptionisthrownatruntime.
C.TheattributeidintheItemobjectremainsunchanged.
D.TheattributeidintheItemobjectismodifiedtothenewvalue.
E.AnewItemobjectiscreatedwiththepreferredvalueintheidattribute.
第2题:
下列程序的输出结果是 interface Inter{ public final static int A=100; } class My implements Inter{ public static void main (String args[ ]) {System.out.println(A) ; }
A.100
B.0
C.A
D.程序有错误
第3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4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5题:
public class ItemTest { private final mt id; public ItemTest(int id) { this.id = id; } public void updateId(int newId) { id = newId; } public static void main(String[] args) { ItemTest fa = new ItemTest(42); fa.updateId(69); System.out.println(fa.id); } } What is the result?()
第6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7题:
作为Java应用程序入口的main方法,其声明格式可以是()。
第8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9题:
public class Wow { public static void go(short n) {System.out.println(”short”); } public static void go(Short n) {System.out.println(”SHORT”);} public static void go(Long n) {System.out.println(” LONG”); } public static void main(String [] args) { Short y= 6; int z=7; go(y); go(z); } } What is the result?()
第10题:
Compilation fails.
An exception is thrown at runtime.
The attribute id in the Item object remains unchanged.
The attribute id in the Item object is modified to the new value.
A new Item object is created with the preferred value in the id attribute.
第11题:
int Long
Short Long
Compilation fails.
An exception is thrown at runtime.
第12题:
s 14
s 16
s 10
Compilation fails.
An exception is thrown at runtime.
第13题:

A.Compilation fails.
B.exception is thrown at runtime.
C.The attribute id in the ItemTest object remains unchanged.
D.The attribute id in the ItemTest object is modified to the new value.
E.A new ItemTest object is created with the preferred value in the id attribute.
第14题:
下列程序段中,正确的是______。 ①class MvClass { int var = 100; static int getVar() { return var; } } ②public class MyClass { final int date; void MyClass (int d) { date = d; } } ③public class MyMain { public static void main(String args[]) { System.out.println(Myclass1.date); } } class MyClass1 { int data = 10; } ④class IamAbstract { final int f; double d; abstrct void method(); }
A.②④
B.①③
C.②
D.以上都不对
第15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16题:
以下是JAVA中正确的入口方法是? ()
第17题:
Which declarations will allow a class to be started as a standalone program?()
第18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19题:
public class TestDemo{ private int x = 2; static int y = 3; public void method(){ final int i=100; int j = 10; class Cinner{ public void mymethod(){ //Here } } } } 在Here处可以访问的变量是哪些?()
第20题:
public class Yikes { public static void go(Long n) {System.out.println(”Long “);} public static void go(Short n) {System.out.println(”Short “);} public static void go(int n) {System.out.println(”int “);} public static void main(String [] args) { short y= 6; long z= 7; go(y); go(z); } } What is the result?()
第21题:
0
1
2
Compilation fails.
第22题:
public static void main(String[] args){}
public static void main(String args){}
public void main(String[] args){}
public static int main(String[] args){}
第23题:
Compilation fails.
exception is thrown at runtime.
The attribute id in the ItemTest object remains unchanged.
The attribute id in the ItemTest object is modified to the new value.
A new ItemTest object is created with the preferred value in the id attribute.
第24题:
1
2
3
编译失败