- Which of the following statement is true
a. You can directly read text from a FileReader.
b. You can directly write text to a File Reader.
c. You can directly read ints and floats from a FileReader.
d. You can directly write longs and shorts to a FileWriter.
Answer : a)
- What type of data would you read from the java.io.DataInputStream class ?
a. Reference type
b. Primitive type
c. Objects
d. Function
Answer : b)
- How many bytes does the following code write to file dest ?
try
{
FileOutputStream fos = new FileOutputStream (“dest”);
DataOutputStream dos = new DataOutputStream (fos);
dos.writeInt(3);
dos.writeDouble(0.0001);
dos.close ( );
fos.close( );
}
a. 2
b. 8
c. 12
d. 16
Answer : c)
- A file created with the following code:
FileOutputStream fos = new FileOutputStream (“datafile”);
DataOutputStream dos = new DataOutputStream (fos);
for(int i= 0; i<500; i++)
dos.writeInt(i);
a.Construct a FileInputStream, passing the name of the file. Onto the FileInputStream, chain a DataInputStream, and call it readInt( ) method.
b. Constructor a FileReader, passing the name of the file. Call the file reader’s readInt ( ) method.
c. Constructor a PipedInputStream, passing the name of the file. Call the piped input stream’s readInt( ) method.
d.Constructor a FileWriter, passing the name of the file. Onto the FileWriter, chain a DataInputStream, and call it readInt ( ) method.
Answer : a)
- Which of the following is true?
a. You cannot directly read text from a FileReader.
b. You can directly write text to a FileWriter.
c. You can directly read ints and floats from a FileReader.
d. You can directly write longs and shorts to a FileWriter.
Answer : b)
- A java stream is :
a. The flow of control through a function.
b. Associated with a particular class
c. A file.
d. A flow of data from one place to another.
Answer : d)
- Consider square number defined as follows:
square (1) = 1
square (N) = square (N-1)+2N-1
According to this definition, what is square(3)?
a. square (3) = square (2) + square (1)
b. square (3) = square (2) – 2*3 + 1
c. square (3) = square (2) + 2*3 – 1
d. square (3) = square (3) + 2*3 – 1
Answer : c)
Java MCQ Set-4 Explanation
- Look at the square numbers one more time:
square (1) = 1
square (N) = square (N-1) + 2N-1
Assume the definition has been implemented correctly. How many invocations will there be on the call stack if main ( ) calls square (5)?
a. 1
b. 3
c. 5
d. 6
Answer : c)
Java MCQ Set-4 Explanation
- When creating a subclass, what keyword is used to include a superclass?
a. extends
b. static
c. this
d. implement
Answer : a)
- How does a subclass execute its superclass constructor?
a. static ( )
b. super( )
c. this ( )
d. extends ( )
Answer : b)