Files and I/O

Files and I/O

Easy Questions

JAVA Programming

Java Basic
Basic Syntax
Object & Classes
Basic Datatypes
Variable Types
Modifier Types
Basic Operators
Loop Control
Decision Making
Numbers
Characters
Strings
Arrays
Date & Time
Regular Expressions
Methods
Files and I/O
Exceptions
Inheritance
Polymorphism
Abstraction
Encapsulation
Interfaces
Packages
Data Structures
Collections
Generics
Serialization
Networking
Multithreading
Applet
  1. What is the output of this program?
    public class output
        {
            public static void main(String args[])
            { 
               StringBuffer s1 = new StringBuffer("Interview");
               s1.setCharAt(8,'W');
               System.out.println(s1);
            }
        }










  1. View Hint View Answer Discuss in Forum

    NA

    Correct Option: D

    IntervieW

  1. What is the output of this program?
    public class IndexOf_Example
        {
            public static void main(String args[])
            {
                String str="My first love is java.";
                System.out.println(str.indexOf('i')+" "+str.indexOf('o')+" "+str.lastIndexOf('i')+" "+str.lastIndexOf('j') );
            }
        }










  1. View Hint View Answer Discuss in Forum

    NA

    Correct Option: C

    indexof(‘c’) and lastIndexOf(‘j’) are pre defined function which are used to get the index of first and last occurrence of
    the character pointed by j in the given array.

  1. What is the output of this program?
    public class Result
        {
            public static void main(String args[])
            {
                char array[]={'a','1','b',' ','A','0'};
                for (int k = 0; k < 5; ++k)
                {
    	        if(Character.isDigit(array[k]))
                        System.out.println(array[k]+" is a digit");
                    if(Character.isWhitespace(array[k]))
                       System.out.println(array[k]+" is a Whitespace character");
                    if(Character.isUpperCase(array[k]))
                       System.out.println(array[k]+" is an Upper case Letter");
                    if(Character.isLowerCase(array[k]))
                       System.out.println(array[k]+" is a lower case Letter");
                    k = k + 3;
                }
            }
        }










  1. View Hint View Answer Discuss in Forum

    NA

    Correct Option: A

    Character.isDigit(array[k]),Character.isUpperCase(array[k]),Character.isWhitespace(array[k]) are the function of library java.lang
    they are used to find weather the given character is of specified type or not. They return true or false i:e Boolean variable.

  1. What is the output of this program?
    public class Result
        {
            public static void main(String args[])
            { 
               StringBuffer strbuf = new StringBuffer("Interview Mania");
               StringBuffer strbuf0 = strbuf.reverse();
               System.out.println(strbuf0);
            }
        }










  1. View Hint View Answer Discuss in Forum

    NA

    Correct Option: B

    reverse() method reverses all characters. It returns the reversed object on which it was called.

  1. What is the output of this program?
    import java.io.*;
        public class InputStream_Example
        {
            public static void main(String args[]) throws IOException
            {
                InputStream obj = new FileInputStream("Interviewmania.com");
                System.out.print(obj.available());
            }
        }










  1. View Hint View Answer Discuss in Forum

    NA

    Correct Option: B

    Exception in thread "main" java.io.FileNotFoundException: Interviewmania.com (No such file or directory)
    	at java.io.FileInputStream.open0(Native Method)
    	at java.io.FileInputStream.open(FileInputStream.java:195)
    	at java.io.FileInputStream.(FileInputStream.java:138)
    	at java.io.FileInputStream.(FileInputStream.java:93)
    	at InputStream_Example.main(InputStream_Example.java:6)