SAIL Sample Technical Placement Paper

7/29/2019 SAIL Sample Technical Placement Paper

1/9

Visit www.latestoffcampus.com for placement papers, interview tips & job updates. Toget

freeupdates tomail http://groups.google.com/group/latestoffcampus/subscribeLive updates on

Facebook @ www.facebook.com/LatestOffCampus




SAIL Technical Latest Sample Placement Paper

1. What does Option Explicit refer to?

ANS: All variables must be declared before use. Their type is not

required.

2.What are the ADO objects?

ANS: Provide a scenario using three of them to return data from a

database. Expected answer: Connection Connects to a data source;

contains the Errors collectionCommand Executes commands to the

data source. Is the only object that can accept parameters for a stored

procedure.Recordset The set of data returned from the

database.Scenario: There are many possibilities. The most likely is as

follows:

Dim conn As ADODB.ConnectionDim rs As ADODB.RecordsetDim Cmd

As ADODB.Commandconn.ConnectionString =? CONNECTION STRING?

conn.OpenSet Cmd.ActiveConnection = connCmd.CommandText =? SQL

STATEMENT? Set rs = Cmd.ExecuteSet rs.ActiveConnection =

Nothingconn.Close

3.What are some benefits of using MTS?

ANS: Database Pooling, Transactional operations, Deployment,

Security, Remote Execution.

4.Dim x, y as integer. What is x and y data type?

ANS: X as variant and y as integer.

5.What is the Dll required for running the VB?

ANS: Vbrun300.dll

6.What is the diff between the Std and Class Module?

ANS: Std Global with in the project. Cls Global throughout the all

project only thing is we want to set the type lib. Class Modules can be

Instantiated.


2/9







7.What is the size of the variant data type?

ANS: The Variant data type has a numeric storage size of 16 bytes and

can contain data up to the range of a Decimal, or a character storagesize of 22 bytes (plus string length),and can store any character text.

8.What are the record set types?

ANS: RdOpenFowardOnly 0 (Default used only for the read only

purpose)

RdOpenStatic 1

RdOpenDynamic 2

RdOpenKeySet 3 (Normally used for the live project)

9.What is DBFailError?

ANS: Rolls Back updates if any errors Occurs.

10.Private Dim x as integer. Valid?

ANS: Private cannot be used in front of DIM.

11.Can we able to set Instancing properties like Singleuse,

GlobalSingleuse to ActiveXDll?

ANS: No.

12.What are properties available in Clip Board?

ANS: No Properties Available. Only the methods they are SetText,

GetText, Setdata (), Getformat (), Clear.

13.What the RDO Methods and Events?

ANS: Methods Events

Begin Trans ValidateCommit Trans Reposition

Rollback Trans Error

Cancel Query Complied

Refresh


3/9







Update Controls

Update row

14.What is MAPI?

ANS: Messaging Application programming Interface.

15.What are the locks available in Visual Basic?

ANS: Locking is the process by which a DBMS restricts access to a row in

multi-user environment 4 types of locks. They are

1. Batch Optimistic

2. Optimistic

3. Pessimistic4. Read Only

Operations in a relational database act on a complete set of rows. The

set of rows returned by a SELECT statement consists of all the rows that

satisfy the conditions in the WHERE clause of the statement. This

complete set of rows returned by the statement is known as the result

set.

Applications, especially those that are interactive and online, cannot

always work effectively with the entire result set as a unit.These applications need a mechanism to work with one row or a small

block of rows at a time. Cursors are an extension to result sets that

provide that mechanism.

Cursor or lock type Advantages Disadvantages AdOpenForwardOnly

(Default) Low resource requirements Cannot scroll backward No data

concurrency AdOpenStatic Scrollable (Wont detect changes made at

the same time by another application) No data concurrency

AdOpenKeyset Some data concurrency Scrollable Higher resource

requirements Not available in disconnected scenario AdOpenDynamic

High data concurrency Scrollable Highest resource requirements Not

available in disconnected scenario AdLockReadOnly Low resource

requirements Highly scalable Data not updatable through cursor


4/9







AdLockBatchOptimistic Batch updates Allows disconnected scenarios

Other users able to access data Data can be changed by multiple users

at once AdLockPessimistic Data cannot be changed by other users while

locked Prevents other users from accessing data while locked

AdLockOptimistic Other users able to access data Data can be changed

by multiple users at once.

16.What is Tabstrip control?

ANS: Libraries of procedure external to the application but can be

called from the application.

17.What is DBSqlPassThrough?

ANS: It will By Passing the Jet Query Processor.

18.What is the difference between a constructor and a method?

ANS: A constructor is a member function of a class that is used to

create objects of that class. It has the same name as the class itself, has

no return type, and is invoked using the new operator. A method is an

ordinary member function of a class. It has its own name, a return type

(which may be void), and is invoked using the dot operator.

19.What is the starting Index value? How to locate it?

ANS: It is tab control to place our controls with in the form in multiple

sheets.

Index starts with 1.

And to identify If Tabstrip1.SelectedItem.

Index = 1 Then..

End if

20.What is keyword used to compare to objects?

ANS: ISOperator Returns Boolean.

21.Where will we give the option explicit keyword and for what?

ANS: In the general declarations section. To trap undeclared variables.


5/9







22.What is Implicit?

ANS: Instance of specific copy of a class with its own settings for the

properties defined in that class.Note: The implicitly defined variable is never equal to nothing.

23.What is the return type of Instr and Strcmp?

ANS: Instr integer (Numeric position)

Strcmp - integer ( if both the string are equal they result = 0)

Strcmp (Str1, Str2, Comparetype)

Comparing mode = 0 Binary Comparing 1 Textual Comparing.

24.What is Iterators?

ANS: Some of the collection classes provide traversal of their contents

via a java.util.Iterator interface. This interface allows you to walk a

collection of objects, operating on each object in turn. Remember when

using Iterators that they contain a snapshot of the collection at the time

the Iterator was obtained; generally it is not advisable to modify the

collection itself while traversing an Iterator.

25.State the significance of public, private, protected, default modifiers

both singly and in combination and state the effect of packagerelationships on declared items qualified by these modifiers?

ANS: public: Public class is visible in other packages, field is visible

everywhere (class must be public too) private: Private variables or

methods may be used only by an instance of the same class that

declares the variable or method, A private feature may only be

accessed by the class that owns the feature.protected: Is available to all

classes in the same package and also available to all subclasses of the

class that owns the protected feature. This access is provided even to

subclasses that reside in a different package from the class that owns

the protected feature.default: What you get by default i.e., without any

access modifier (ie, public private or protected).It means that it is

visible to all within a particular package.


6/9







26.What is an abstract class?

ANS: Abstract class must be extended/subclassed (to be useful). It

serves as a template. A class that is abstract may not be instantiated(i.e., you may not call its constructor), abstract class may contain static

data. Any class with an abstract method is automatically abstract itself,

and must be declared as such. A class may be declared abstract even if

it has no abstract methods. This prevents it from being instantiated.

27.What is static in java?

ANS: Static means one per class, not one for each object no matter how

many instance of a class might exist. This means that you can use them

without creating an instance of a class. Static methods are implicitly

final, because overriding is done based on the type of the object, and

static methods are attached to a class, not an object. A static method in

a superclass can be shadowed by another static method in a subclass,

as long as the original method was not declared final. However, you

cant override a static method with a nonstatic method. In other words,

you cant change a static method into an instance method in a subclass.

28.What is Externalizable interface?ANS: Externalizable is an interface which contains two methods

readExternal and writeExternal. These methods give you a control over

the serialization mechanism. Thus if your class implements this

interface, you can customize the serialization process by implementing

these methods.

29.Do I need to import java.lang package any time? Why?

ANS: No. It is by default loaded internally by the JVM.

30.How can we call Stored procedure of Back End in RDO and ADO ?

ANS: In RDO We can call using RDO Query Objects.

In ADO We can call using Command Objects.


7/9







31.Can I have multiple main methods in the same class?

ANS: No the program fails to compile. The compiler says that the main

method is already defined in the class.32.Can I import same package/class twice?

Will the JVM load the package twice at runtime?

ANS: One can import the same package or same class multiple times.

Neither compiler nor JVM complains abt it. And the JVM will internally

load the class only once no matter how many times you import the

same class.

33.Difference between Vector and ArrayList?

ANS: Vector is synchronized whereas arraylist is not.

34.What are pass by reference and passby value?

ANS: Pass By Reference means the passing the address itself rather

than passing the value. Passby Value means passing a copy of the value

to be passed.

35.Explain different way of using thread?

ANS: The thread could be implemented by using runnable interface orby inheriting from the Thread class. The former is more advantageous,

because when we are going for multiple inheritance. The only interface

can help.

36.What is mutual exclusion? How can you take care of mutual

exclusion using Java threads?

ANS: Mutual exclusion is where no two processes can access critical

regions of memory at the same time. Java provides many utilities to

deal with mutual exclusion with the use of threaded programming.For mutual exclusion, you can simply use the synchronized keyword

and explicitly or implicitly provide an Object, any Object, to synchronize

on.

The runtime system/Java compiler takes care of the gruesome details


8/9







for you. The synchronized keyword can be applied to a class, to a

method, or to a block of code. There are several methods in Java used

for communicating mutually exclusive threads such as wait ( ), notify ( ),

or notifyAll ( ). For example, the notifyAll ( ) method wakes up all

threads that are in the wait list of an object.

37.What are some advantages and disadvantages of Java Sockets?

ANS: Some advantages of Java Sockets:

Sockets are flexible and sufficient. Efficient socket based programming

can be easily implemented for general communications.

Sockets cause low network traffic. Unlike HTML forms and CGI scripts

that generate and transfer whole web pages for each new request, Javaapplets can send only necessary updated information.

Some disadvantages of Java Sockets:

Security restrictions are sometimes overbearing because a Java applet

running in a Web browser is only able to establish connections to the

machine where it came from, and to nowhere else on the network

Despite all of the useful and helpful Java features, Socket based

communications allows only to send packets of raw data between

applications. Both the client-side and server-side have to provide

mechanisms to make the data useful in any way.

Since the data formats and protocols remain application specific, the

re-use of socket based implementations is limited.

38.What are different types of inner classes?

ANS: They are Nested -level classes, Member classes, Local classes,

Anonymous classes

Nested -level classes- If you declare a class within a class and specifythe static modifier, the compiler treats the class just like any other -

level class. Any class outside the declaring class accesses the nested

class with the declaring class name acting similarly to a package. eg,

outer.inner. -level inner classes implicitly have access only to static


9/9







variables. There can also be inner interfaces. All of these are of the

nested -level variety.

Member classes Member inner classes are just like other member

methods and member variables and access to the member class is

restricted, just like methods and variables. This means a public member

class act similarly to a nested -level class. The primary difference

between member classes and nested -level classes is that member

classes have access to the specific instance of the enclosing class.

Local classes Local classes are like local variables, specific to a block of

code. Their visibility is only within the block of their declaration. In

order for the class to be useful beyond the declaration block, it wouldneed to implement a more publicly available interface. Because local

classes are not members; the modifiers public, protected, private, and

static are not usable.

Anonymous classes Anonymous inner classes extend local inner

classes one level further. As anonymous classes have no name, you

cannot provide a constructor.

39.What is the difference between declaring a variable and defining a

variable?ANS: In declaration we just mention the type of the variable and its

name. We do not initialize it. But defining means declaration +

initialization. E.g. String s; is just a declaration while String s = new

String (abcd); Or String s = abcd; are both definitions.

40.What is the default value of an object reference declared as an

instance variable?

ANS: Null unless we define it explicitly.

SAIL Sample Technical Placement Paper

Documents

Transcript of SAIL Sample Technical Placement Paper