新华信国际信息咨询JAVA工程师笔试题和面试题答案(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
