Skip to main content

Q) Explain about “+” operator in java ?



A)
->it is a binary operator i.e., it acts upon two operands.
->it is the only operator that is overloaded in java.
->it acts both as arithmetic addition operator and string concatenation operator. Is both are operands are of numerical type; it acts as arithmetic addition operator. If at least one of the operands is a string it acts as string concatenation operator.
Note: operator overloading feature is not there in java
Ex: int a=10;
Int b= 30;
Int c= a+b;
System.out.println(“the sum  :”+a+b);
here o/p is sum is 1030
System.out.println(“the sum  :”+(a+b));
Here o/p is 40
->in c++ program has flexibility. The operator functionality can be overloading in many cases.
->in java “+“is the operator implementing polymorphism (as “+” is behaving different in different situations).

Comments

Post a Comment

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.  
Post a Comment
Read more

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 : " );      ...
Post a Comment
Read more

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.
Post a Comment
Read more