【IT168 技术文档】
Question 9:What code placed after the comment:
// Start For loop
would populate the elements of the array ia[] with values of the variables i ?
public class Lin{
public static void main(String argv[]){
Lin l = new Lin();
l.amethod();
}
public void amethod(){
int ia[] = new int[4];
// Start For loop
{
ia[i] = i;
System.out.println(ia[i]);
}
}
}
A. for(int i=0; i
B. for (int i=0; i
C. for(int i=0; i<4; i++)
D. for(int i=0; i
Question 10:Consider the following code:
Integer s = new Integer(9);
Integer t = new Integer(9);
Long u = new Long(9);
Which test would return true?
A. (s==u)
B. (s==t)
C. (s.equals(t))
D. (s.equals(9))
E. (s.equals(new Integer(9))
Question 11:Which of the following is successfully create an instance of the Vector class and add an element?
A. Vector v = new Vector(99);
v[1]=99;
B. Vector v = new Vector();
v.addElement(99);
C. Vector v = new Vector();
v.add(99);
D. Vector v = new Vector(100);
v.addElement(“99”);
Question 12:What will happen when you attempt to compile and run the following code?
class Base{
private void amethod(int iBase){
System.out.println(“Base.amethod”);
}
}
class Over extends Base{
public static void main(String argv[]){
Over o = new Over();
int iBase=0;
o.amethod(iBase);
}
public void amethod(int iOver){
System.out.println(“Over.amethod”);
}
}
A. Compile time error complaining that Base.amethod is private
B. Runtime error complaining that Base.amethod is private
C. Output of Base.amethod
D. Output of Over.amethod
Question 13:What will happen if you try to compile and run the following code?
public class MyClass
public static void main(String arguments[]){
amethod(arguments);
}
public void amethod(String[] arguments)
System.out.println(arguments);
System.out.println(arguments[1]);
}
}
A. Error can’t make static reference to void amethod
B. Error method main not correct
C. Error array must include parameter
D. Error amethod must be declared with String
Question 14:If you wanted to find out where the position of the letter v (i.e. return 2) in the string s containing “Java”, which of the following could you use?
A. mid(2,s);
B. charAt(2);
C. s.indexOf(‘v’);
D. indexOf(s,’v’);
Question 15:What will happen when you attempt to compile and run the following code?
public class Bground extends Thread{
public static void main(String argv[]){
Bground b = new Bground();
b.run();
}
public void start(){
for (int i=0;i<10;i++){
System.out.println(“Value of i=” + i);
}
}
}
A. A compile time error indicating that no run method is defined for the Thread class
B. A run time error indicating that no run method is defined for the Thread class
C. Clean compile and at run time the values 0 to 9 are printed out
D. Clean compile but no output at runtime
Question 16:What will happen when you compile the following code?
public class MyClass{
static int i;
public static void main(String argv[]){
System.out.println(i);
}
}
A. Error Variable i may out have been initialized
B. null
C. 1
D. 0
