Interview Questions

If you need to support random access, without inserting or removing elements from any place other than the end, then ArrayList offers the optimal collection. If, however, you need to frequently add and remove elements from the middle of the list and only access the list elements sequentially, then LinkedList offers the better implementation.

A collection just like an array is an ordered group of elements of the same type. Each elements position is determined by a unique subscript.

Index by tables:- They are similar to hash arrays that allows to search for subscript values using arbitrary numbers and strings.

They can be declared as:

TYPE type_name IS TABLE OF element_type [NOT NULL]

INDEX BY [BINARY_INTEGER | PLS_INTEGER | VARCHAR2(size_limit)];

INDEX BY key_type;

Example:

TYPE studenttyp IS TABLE OF emp%ROWTYPE

INDEX BY BINARY_INTEGER;

stud_tab studenttyp;

Nested tables:- they hold random number of elements and use sequential numbers as sub scripts.

They can be declared as:

TYPE type_name IS TABLE OF element_type [NOT NULL];

Example: TYPE employee_type IS TABLE OF NUMBER INDEX BY VARCHAR2(64);

Varrays: Holds a fixed number of elements which can be changed in run time. 

They can be declared as:

TYPE type_name IS {VARRAY | VARYING ARRAY} (size_limit) OF element_type [NOT NULL];

Example: TYPE Calendar IS VARRAY(366) OF DATE;

-  A stored procedure can accept parameters while a trigger cannot.
-  A trigger can’t return any value while stored procedures can.
-  A trigger is executed automatically on some event while a stored procedure needs to be explicitly called.
-  Triggers are used for insertions, update and deletions on tables while stored procedures are often using independently in the database.
-  A trigger cannot be written in a stored procedure. However, the reverse is not possible.

Wage Revisions as per wage policy every finanical year means April of the every year will revised.

At the same time Basic is revised as per appointment order like we are given probation period to every employee after completion of the employee probation than basic also revised and depends upon Organisation Structure also.

The LMHOSTS file is a static method of resolving NetBIOS names to IP addresses in the same way that the HOSTS file is a static method of resolving domain names into IP addresses. An LMHOSTS file is a text file that maps NetBIOS names to IP addresses; it must be manually configured and updated.

Node.js is a framework for web applications built on Google Chrome's JavaScript Engine(V8 Engine).

Node.js is comes with runtime environment on which a cript based on javascript can be interpreted and executed (It is analogus to JVM to JAVA byte code). This runtime environment allows to execute a JavaScript code on any machine outside a browser. Because of this runtime of Node.js, JavaScript is now can be executed on server also.

Node.js is provides a rich library of various javascript modules which eases the developement of web application using Node.js to greater extents.

-The shift() method is similar as the pop() method but the difference is that Shift method works at the beginning of the array. 

-The shift() method take the first element off of the given array and returns it. The array on which is called is then altered.

For example

var myarray = ["apple ", "banana ", "mango "]; 

console.log(myarray.shift());

console.log(myarray);

we get the following console output:

apple

["banana ", "mango "];

When we call shift() on an empty array, it will return an undefined value.