Questions and answers for exam Preparation

MCQs

Total Questions : 10

What is the output of this program?

package pkg;
class output {
public static void main(String args[])
{
StringBuffer s1 = new StringBuffer("Hello World");
s1.insert(6 , "Good ");
System.out.println(s1);
}
}

Note : Output.class file is not in directory pkg.

HelloGoodWorld
HellGoodoWorld
Compilation error
Runtime error

Discuss Question

Answer: Option D. -> Runtime error

Since output.class file is not in the directory pkg in which class output is defined, program will

not be able to run.
output:
$ javac output.java
$ java output
can not find file output.class

Question 2.

What is the output of this program?

package pkg;
class output {
public static void main(String args[])
{
StringBuffer s1 = new StringBuffer("Hello");
s1.setCharAt(1, x);
System.out.println(s1);
}
}

xello
xxxxx
Hxllo
Hexlo

Discuss Question

Answer: Option C. -> Hxllo

None.
Output:
$ javac output.java
$ java output
Hxllo

Question 3.

What is the output of this program?

package pkg;
class display {
int x;
void show() {
if (x > 1)
System.out.print(x + " ");
}
}
class packages {
public static void main(String args[]) {
display[] arr=new display[3];
for(int i=0;i

0
1
2
0 1 2

Discuss Question

Answer: Option C. -> 2

None.
Output:
$ javac packages.java
$ java packages
2

Question 4.

Which of the following package stores all the standard java classes?

lang
java
util
java.packages

Discuss Question

Answer: Option B. -> java

None.

Question 5.

Which of the following is incorrect statement about packages?

Package defines a namespace in which classes are stored.
A package can contain other package within it.
Java uses file system directories to store packages.
A package can be renamed without renaming the directory in which the classes are stored.

Discuss Question

Answer: Option D. -> A package can be renamed without renaming the directory in which the classes are stored.

A package can be renamed only after renaming the directory in which the classes are stored.

Question 6.

Which of the following is correct way of importing an entire package â€˜pkgâ€™?