SCJP Input Output
By: admin - Tuesday, September 9th, 2008 at 10:54 am
QUESTION : 1
You can create a RandomAccessFile object in the following manner
FileInputStream fis = new FileInputStream("file path");
RandomAccessFile raf = new RandomAccessFile(fis , "rw");
1. False.
2. True
ANS : 1
QUESTION : 2
What is the result of attempting to compile and run this ?
public class Test {
public static void main(String[] args){
byte out = 0;
RandomAccessFile raf;
try{
raf = new RandomAccessFile("test1.txt" , "rw");
for (int i=0; i<10; i++)
raf.write(i);
raf.seek(1);
out = raf.readByte();
raf.close();
System.out.println(out);
}
catch(IOException e){System.out.println("err");}
}
}
1. 1
2. 0
ANS : 1
QUESTION : 3
What is the result of attempting to compile and run this ?
public class Test {
public static void main(String[] args){
byte out = 0;
String f = "test.txt";
RandomAccessFile raf;
try{
raf = new RandomAccessFile(f , "rw");
raf.write(1);
raf.close();
raf.open(f, true);
raf.seek(1);
out = raf.readByte();
raf.close();
System.out.println(out);
}
catch(IOException e){System.out.println("err");}
}
}
1. It will run and print "err"
2. It will run and print "1"
3. It will throw a runtime exception
4. It will not compile
ANS : 4
QUESTION : 4
Which of the fllowing will create a file called test.txt
in your current directory ?
1. File f = new File("test.txt");
2. FileOutputStream fos = new FileOutputStream("test.txt");
3. RandomAccessFile raf = new RandomAccessFile("test.txt", "r");
4. RandomAccessFile raf = new RandomAccessFile("test.txt", "rw");
ANS : 2,4
QUESTION : 5
True or false.
UTF characters are always 16 bits
1. True
2. False
ANS : 2
QUESTION : 6
void aMethod(){
File f = new File("test.txt");
try{ f.createNewFile();}
catch(Exception e){System.out.println("err");}
}
Calling this method will overwrite the existing file an create
a blank file in its place.
1. True
2. False
ANS : 2
QUESTION : 7
Which of the following are valid constructors for
a DataInputStream ?
1. DataInputStream(FileInputStream fis)
2. DataInputStream(DataInputStream dis)
3. DataInputStream(File f)
4. DataInputStream(FilterInputStream fis)
ANS : 1,2,4
QUESTION : 8
True or false ?
InputStreamReader is a subclass of InputStream
1. True
2. False
ANS : 2
QUESTION : 9
This is a valid constructor for a BufferedReader.
BufferedReader(FileReader fr)
True or false?
1. True
2. False
ANS : 1
QUESTION : 10
Now you get a bonus mark.
ANS : 1