1. Which of these is a method to clear all the data present in output buffers?
a) clear()
b) flush()
c) fflush()
d) close()
Discussion
Explanation: flush()
2. Which of these method(s) is/are used for writing bytes to an outputstream?
a) put()
b) print() and write()
c) printf()
d) write() and read()
Discussion
Explanation: print() and write()
3. What will be the output of the following Java program?
import java.io.*;
public class filesinputoutput
{
public static void main(String[] args)
{
String obj = "abc";
byte b[] = obj.getBytes();
ByteArrayInputStream obj1 = new ByteArrayInputStream(b);
for (int i = 0; i < 2; ++ i)
{
int c;
while ((c = obj1.read()) != -1)
{
if(i == 0)
{
System.out.print((char)c);
}
}
}
}
}
a) abc
b) ABC
c) ab
d) AB
Discussion
Explanation:
Output:
abc
4. What will be the output of the following Java program?
import java.io.*;
public class filesinputoutput
{
public static void main(String[] args)
{
String obj = "abc";
byte b[] = obj.getBytes();
ByteArrayInputStream obj1 = new ByteArrayInputStream(b);
for (int i = 0; i < 2; ++ i)
{
int c;
while ((c = obj1.read()) != -1)
{
if (i == 0)
{
System.out.print(Character.toUpperCase((char)c));
}
}
}
}
}
a) abc
b) ABC
c) ab
d) AB
Discussion
Explanation:
Output:
ABC
5. What will be the output of the following Java program?
import java.io.*;
public class filesinputoutput
{
public static void main(String[] args)
{
String obj = "abc";
byte b[] = obj.getBytes();
ByteArrayInputStream obj1 = new ByteArrayInputStream(b);
for (int i = 0; i < 2; ++ i)
{
int c;
while ((c = obj1.read()) != -1)
{
if (i == 0)
{
System.out.print(Character.toUpperCase((char)c));
obj2.write(1);
}
}
System.out.print(obj2);
}
}
}
a) AaBaCa
b) ABCaaa
c) AaaBaaCaa
d) AaBaaCaaa
Discussion
Explanation:
Output:
AaBaaCaaa
6. Which of the following is not a segment of memory in java?
a) Stack Segment
b) Heap Segment
c) Code Segment
d) Register Segment
Discussion
Explanation: There are only 3 types of memory segment. Stack Segment, Heap Segment and Code Segment.
7. Does code Segment loads the java code?
a) true
b) false
Discussion
Explanation: Code Segment loads compiled java bytecode. Bytecode is platform independent.
8. What is JVM?
a) Bootstrap
b) Interpreter
c) Extension
d) Compiler
Discussion
Explanation: JVM is Interpreter. It reads .class files which is the byte code generated by compiler line by line and converts it into native OS code.
9. Which one of the following is a class loader?
a) Bootstrap
b) Compiler
c) Heap
d) Interpreter
Discussion
Explanation: Bootstrap is a class loader. It loads the classes into memory.
10. Which class loader loads jar files from JDK directory?
a) Bootstrap
b) Extension
c) System
d) Heap
Discussion
Explanation: Extension loads jar files from lib/ext directory of the JRE. This gives the basic functionality available.