Technology Questions

File[] listFiles();

this method returns list of files stored in a directory.

If we are not using packages and if we are not using inheritance then there is no difference among public, protected and package access data.

Top level class is also called outer class. It is not defined inside any class.

Ex:

class A {  //top level class

}

Constructor is not a special method.

Constructor is block of code that is executed automatically whenever object of the class is created.

Both JavaScript and Jscript are almost similar. JavaScript was developed by Netscape. Microsoft reverse engineered Javascript and called it JScript.

Cursors help you manipulate the information retrieved by select statements. This can be done by assigning a name to the cursor.

Example:

CURSOR emp_cur 

IS 

SELECT emp_number from employee_tbl where employee_name = name_in;

Types of Cursors:

Implicit cursors- These cursors are not declared by the programmer. They are issued when the SQL statement is executed. The open, close and fetching is done by itself.

Example:

UPDATE employee SET salary = salary * 2.1;

Here, an implicit cursor is issued to identify the set of rows in the table which would be affected by the update.

Explicit cursors- These cursors are defined by programmer. They are used in queries that return multiple rows.

Example:

CURSOR emp_cur 

IS 

SELECT emp_number from employee_tbl where employee_name = name_in;

It is the ability of an object to behave differently on different situations for the same message.

Number, String, Boolean, Function, Object, Null, Undefined.