新華信國際信息咨詢JAVA工程師筆試題和面試題答案(三)

　　D.8

　　8:

　　String s=”Example String”;Which operation is not legal?

　　String s=”Example String”;Which operation is not legal?

　　A.int i=s.length();

　　B.s[3]=”x”;

　　C.String short_s=s.trim();

　　D.String t=”root”+s;

　　9:

　　Give this class outline:

　　class Example{

　　private int x;

　　//rest of class body…

　　}

　　Assuming that x invoked by the code java Example, which statement can made x be directly accessible in main() method of Example.java?

　　Give this class outline:

　　class Example{

　　private int x;

　　//rest of class body…

　　}

　　Assuming that x invoked by the code java Example, which statement can made x be directly accessible in main() method of Example.java?

　　A.Change private int x to public int x

　　B.change private int x to static int x

　　C.Change private int x to protected int x

　　D.change private int x to final int x

　　10:

　　What will happen when you attempt to compile and run the following code?

　　class Base

　　{

　　int i = 99;

　　public void amethod()

　　{

　　System.out.println("Base.amethod()");

　　}

　　Base()

　　{

　　amethod();

　　}

　　}

　　public class Derived extends Base

　　{

　　int i = -1;

　　public static void main(String argv[])

　　{

　　Base b = new Derived();

　　System.out.println(b.i);

　　b.amethod();

　　}

　　public void amethod()

　　{

　　System.out.println("Derived.amethod()");

　　}

　　}

　　Choices:

　　What will happen when you attempt to compile and run the following code?

　　class Base

　　{

　　int i = 99;

　　public void amethod()

　　{

　　System.out.println("Base.amethod()");

　　}

　　Base()

　　{

　　amethod();

　　}

　　}

　　public class Derived extends Base

　　{

　　int i = -1;

　　public static void main(String argv[])

　　{

　　Base b = new Derived();

　　System.out.println(b.i);

　　b.amethod();

　　}

　　public void amethod()

　　{

　　System.out.println("Derived.amethod()");

　　}

　　}

　　Choices:

　　A.Derived.amethod() -1 Derived.amethod()

　　B.Derived.amethod() 99

　　C.Compile time error

　　D.Derived.amethod()

　　11:

　　What will be the result of executing the following code?

　　// Filename; SuperclassX.java

　　package packageX;

　　public class SuperclassX

　　{

　　protected void superclassMethodX()

　　{

　　}

　　int superclassVarX;

　　}

　　// Filename SubclassY.java