Skip to main content

Q) java application on constructor overloading?





class book
{
       String title;
       String author;
       float price;
       book()
       {
              title="java complete reference";
              author="schidt";
              price=350;
       }//default constructor
       book(String t,String a,float p)
       {
              title=t;
              author=a;
              price=p;
       }//parameterized constructor
       void displaybookdetails()
       {
              System.out.println("title :"+title);
              System.out.println("author :"+author);
              System.out.println("price :"+price);           
       }
}//class book

class constructoroverloading {

       public static void main(String[] args) {
              book b1=new book();
              System.out.println("first book details");
              b1.displaybookdetails();
              book b2=new book();
              System.out.println("second book details");
              b2.displaybookdetails();
              book b3= new book("yhinking in java","euckle",750);
              System.out.println("third book details");
              b3.displaybookdetails();
       }//main
}//class

A)
Output :

first book details
title :java complete reference
author :schidt
price :350.0
second book details
title :java complete reference
author :schidt
price :350.0
third book details
title :yhinking in java
author :euckle
price :750.0

Comments

Popular posts from this blog

Q) Retrieving data from database?

A)   ->to retrieve the data from database we need to submit SELECT statement from JDBC application. -> executeQuery() method of statement object is used for this purpose. This method has the fallowing ResultSet executeQuery(String sql) throws SQLException Ex: ResultSet rs = st.executeQuery(“SELECT * FROM ACCOUNT”); ->objectoriented representation of tables formate data is called ResultSet object. Ao the driver created one object i.e. ResultSet object. ->object orientation representation of a table of records returned from db is nothing but “ ResultSet ” object.  

Q) Explain repeated deletion of records.

A) //RepeatedDeletion.java import java.util.Scanner; import java.sql.*; class RepeatedDeletion {        public static void main(String[] args) {               Connection con= DriverManager. getConnection ( "jdbc:odbc:prince" , "scott" , "tiger" );               PreparedStatement ps=con.PreparedStatement( "DELETE FROM ACCOUNT WHERE ACCNO=?" );               Scanner s= new Scanner(System. in );               while ( true )               {                      System. out .println( "Enter accno : " );      ...

Q) What is JDBC driver? What is its role in java database connection?

A) ->A translation software written in java according o JDBC specification is nothing but “JDBC driver”. -> JDBC driver implements JDBC API. Use single API. JDBC driver role: They are 4 roles   1)       Establishing connection between JDBC client and database server. 2)       Receiving JDBC method calls made by JDBC client while performing database (CRUD) operations. 3)       Translating java method calls into DBMS understandable calls and forwarding them to database server. 4)       Receiving the results from database server. Translating them into java format and handling over the same to the JDBC client.