Q1. What do you mean by IDE? Is C++ an IDE? If yes, how?
An integrated development environment (IDE), also known as
integrated design environment and integrated debugging environment, is a type
of computer software that assists computer programmers to develop software. In
the case of Visual Basic .NET, that IDE is Visual Studio
An Integrated Development Environment (IDE) is an
application that facilitates application development. In general, an IDE is a
graphical user interface (GUI)-based workbench designed to aid a developer in
building software applications with an integrated environment combined with all
the required tools at hand.
Most common features, such as debugging, version control and
data structure browsing, help a developer quickly execute actions without
switching to other applications. Thus, it helps maximize productivity by
providing similar user interfaces (UI) for related components and reduces the
time taken to learn the language. An IDE supports single or multiple languages.
The concept of IDE evolved from simple command based
software which was not as useful as menu-driven software. Modern IDEs are
mostly used in the context of visual programming, where applications are
quickly created by moving programming building blocks or code nodes that
generate flowchart and structure diagrams, which are compiled or interpreted.
Selecting a good IDE is based on factors, such as language
support, operating system (OS) needs and costs associated with using the IDE
etc.
Q2. What is an Event? What do you mean by event driven
programming?
While you might visualize a Visual Studio project as a
series of procedures that execute in a sequence, in reality, most programs are
event driven—meaning the flow of execution is determined by external
occurrences called events.
An event is a signal that informs an application that
something important has occurred. For example, when a user clicks a control on
a form, the form can raise a Click event and call a procedure that handles the
event. Events also allow separate tasks to communicate. Say, for example, that
your application performs a sort task separately from the main application. If
a user cancels the sort, your application can send a cancel event instructing
the sort process to stop.
In computer
programming, event-driven programming is a programming paradigm in which the
flow of the program is determined by events such as user actions (mouse clicks,
key presses), sensor outputs, or messages from other programs/threads.
Event-driven programming is the dominant paradigm used in graphical user
interfaces and other applications (e.g., JavaScript web applications) that are
centered on performing certain actions in response to user input. This is also
true of programming for device drivers (e.g., P in USB device driver stacks).
In an event-driven application, there is generally a main
loop that listens for events, and then triggers a callback function when one of
those events is detected. In embedded systems, the same may be achieved using
hardware interrupts instead of a constantly running main loop. Event-driven
programs can be written in any programming language, although the task is
easier in languages that provide high-level abstractions, such as await and
closures.
Q3. Explain If-then, If-then else, Case statement using
example.
An If statement
can be followed by an optional Else statement, which executes
when the Boolean expression is false.
Syntax
The
syntax of an If...Then... Else statement in VB.Net is as follows −
If(boolean_expression)Then
'statement(s)
will execute if the Boolean expression is true
Else
'statement(s) will execute if the Boolean expression is false
End If
If the
Boolean expression evaluates to true, then the if block of code
will be executed, otherwise else block of code will be executed.
Flow Diagram
Example
Module decisions
Sub Main()
'local
variable definition '
Dim a As Integer = 100
'
check the boolean condition using if statement
If (a < 20) Then
' if condition is true then print the following
Console.WriteLine("a is less than
20")
Else
'
if condition is false then print the following
Console.WriteLine("a is not less
than 20")
End If
Console.WriteLine("value of a is :
{0}", a)
Console.ReadLine()
End Sub
End
Module
When the
above code is compiled and executed, it produces the following result −
a
is not less than 20
value
of a is : 100
Q4. Is VB being a front end or back end? Explain.
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The emergence of single
page applications introduces a new need for web developers: a front end build
process. Javascript MV* frameworks now allow web developers to build complex
and sophisticated applications with many files (js, css, sass/less, html …).
The
emergence of single page applications introduces a new need for web developers:
a front end build process. Javascript MV* frameworks now allow web developers
to build complex and sophisticated applications with many files (js, css,
sass/less, html …). We’re very far from those 3 lines of JavaScript to put “a
kind of magic” on your web site.
In
traditional back end development such as asp.net MVC, a compiler transforms
source code written in a –human readable- programming language (C#/VB for
asp.net) into another computer language (MSIL for .net). Produced files are
often called binaries or executables. Compilation may contain several
operations: code analysis, preprocessing, parsing, language translation, code
generation, code optimization….What about JavaScript?
JavaScript
was traditionally implemented as an interpreted language, which can be executed
directly inside a browser or a developer console. Most of the examples and
sample applications we’ll find on the web have very basic structure and file
organization. Some developers may think that it’s the “natural way” to build
& deploy web applications, but it’s not.
Nowadays,
we’re now building entire web applications using JavaScript. Working with X
files is merely different. Few frameworks like RequireJS help
us to build modular JavaScript applications thanks to Asynchronous
Module Definitions. Again, this is not exactly what we need here because it
focuses only on scripts.
What
do we need to have today to build a web site? Here are common tasks you may
need:
·
Validate scripts with
JSLint
·
Run tests
(unit/integration/e2e) with code coverage
·
Run preprocessors for
scripts (coffee, typescript) or styles (LESS, SASS)
·
Follow WPO
recommendations (minify, combine, optimize images…)
·
Continuous testing and
Continuous deployment
·
Manage front-end
components
·
Run X, execute Y
So,
what is exactly a front-end build process? An automated way to run one or more
of these tasks in YOUR workflow to generate your production package.
Example front-end build process for an
AngularJS application
Please
note that asp.net Bundling & Minification is a perfect counter-example: it
allows to combine & to minify styles and scripts (two important WPO
recommendations) without having a build process. The current implementation is
very clever but the scope is limited to these features. By the way, I will
still use it for situations where I don’t need a “full control”.
I
talk mainly about Javascript here but it’s pretty the same for any kind of
front-end file here. SASS/LESS/Typescript/… processing is often well integrated
into IDE like Visual Studio but it’s just another way to avoid using a
front-end build process.
Q5.
Explain the various data types in VB. Explain difference between tool bar &
tool box?
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When
you decide to use a variable, you are in fact asking the computer to use a
certain amount of space to hold that variable. Since different variables will
be used for different purposes, you should specify the kind of variable you
intend to use, then the computer will figure out how much space is needed for
a particular variable. Each variable you use will utilize a certain amount of
space in the computer's memory.
Before
declaring or using a variable, first decide what kind of role that variable
will play in your program. Different variables are meant for different
situations. The kind of variable you want to use is referred to as a data
type. To specify the kind of variable you want to use, you type theAs keyword
on the right side of the variable's name. The formula to declare such a
variable is:
Dim VariableName As DataType
Once
you know what kind of variable you will need, choose the appropriate data
type. Data types are organized in categories such as numbers, characters, or
other objects.
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String
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A
string is an empty text, a letter, a word or a group of words considered. To
declare a string variable, use the String data type. Here is an example:
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Private Sub Form_Load()
Dim CountryName As String
End Sub
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After
declaring the variable, you can initialize. If you want its area of memory to
be empty, you can assign it two double-quotes. Here is an example:
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Private Sub Form_Load()
Dim CountryName As String
CountryName = ""
End Sub
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If you
want to store something in the memory space allocated to the variable, assign
it a word or group of words included between double-quotes. Here is an
example:
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Private Sub Form_Load()
Dim CountryName As String
CountryName = "Great Britain"
End Sub
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You can
also initialize a string variable with another.
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Boolean
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A
Boolean variable is one whose value can be only either True or False. To
declare such a variable, use the Boolean keyword. Here is an example:
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Private Sub Form_Load()
Dim IsMarried As Boolean
End Sub
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After
declaring a Boolean variable, you can initialize by assigning it either True
or False. Here is an example:
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Private Sub Form_Load()
Dim IsMarried As Boolean
IsMarried = False
End Sub
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Like
any other variable, after initializing the variable, it keeps its value until
you change its value again.
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Numeric
Data Types
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Introduction
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A
natural number is one that contains only one digit or a combination of digits
and no other character, except those added to make it easier to read.
Examples of natural numbers are 122, 8, and 2864347. When a natural number is
too long, such 3253754343, to make it easier to read, the thousands are
separated by a special character. This character depends on the language or
group of language and it is called the thousands separator. For US English,
this character is the comma. The thousands separator symbol is mainly used
only to make the number easier to read.
To support
different scenarios, Microsoft provides different types of natural numbers
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Byte
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A byte
is a small natural positive number that ranges from 0 to 255. A variable of
byte type can be used to hold small values such as a person's age, the number
of fingers on an animal, etc.
To
declare a variable for a small number, use the Byte keyword. Here
is an example:
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Private Sub Form_Load()
Dim StudentAge As Byte
End Sub
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Integer
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An
integer is a natural number larger than the Byte. It can hold a
value between
-32,768 and 32,767. Examples of such ranges are: the number of pages of a book.
To
declare a variable of type integer, use the Integer keyword.
Here is an example:
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Private Sub Form_Load()
Dim MusicTracks As Integer
End Sub
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Long Integer
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A long
integer is a natural number whose value is between –2,147,483,648 and
2,147,483,642. Examples are the population of a city, the distance between
places of different countries, the number of words of a book.
To
declare a variable that can hold a very large natural number, use the Long keyword.
Here is an example:
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Private Sub Form_Load()
Dim Population As Long
End Sub
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Decimal
Data Types
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Introduction
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A real
number is one that displays a decimal part. This means that the number can be
made of two sections separated by a symbol that is referred to as the Decimal
Separator or Decimal Symbol. This symbol is different by language, country,
group of languages, or group of countries. In US English, this symbol is the
period as can be verified from the Regional (and Language) Settings of the
Control Panel of computers of most regular users:
On both
sides of the Decimal Symbol, digits are used to specify the value of the
number. The number of digits on the right side of the symbol determines how
much precision the number offers.
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Single
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A
single is a decimal number whose value can range from –3.402823e38 and
–1.401298e-45 if the number is negative, or 1.401298e-45 and
3.402823e38 if the number is positive.
To
declare a variable that can hold small decimal numbers with no concern for
precision, use the Single data type. Here is an example:
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Private Sub Form_Load()
Dim CountryName As String
Dim IsMarried As Boolean
Dim StudentAge As Byte
Dim Tracks As Integer
Dim Population As Long
Dim Distance As Single
End Sub
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Double
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While
the Single data type can allow large numbers, it offers less
precision. For an even larger number, Microsoft Visual Basic provides
the Double data type. This is used for a variable that would
hold numbers that range from 1.79769313486231e308 to
–4.94065645841247e–324 if the number is negative or from
1.79769313486231E308 to 4.94065645841247E–324 if
the number is positive.
To
declare a variable that can store large decimal numbers with a good level of
precision, use the Double keyword.
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In most circumstances, it is preferable to use Double instead
of Single when declaring a variable that would hold a decimal
number. Although the Double takes more memory spaces
(computer memory is not expensive anymore(!)), it provides more precision.
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Here is an example of
declaring a Double variable:
Private Sub Form_Load()
Dim Distance As Double
End Sub
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Currency
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The Currency data
type is used for a variable that can hold monetary values. To declare such a
variable, use the Currency keyword. Here is an example:
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Private Sub Form_Load()
Dim CountryName As String
Dim IsMarried As Boolean
Dim StudentAge As Byte
Dim Tracks As Integer
Dim Population As Long
Dim Distance As Single
Dim StartingSalary As Currency
End Sub
Toolbar
The toolbar is a set of
buttons and icons that are part of any software's user interface. In most
cases, the toolbar is located directly below the menu bar. The toolbar has
different icons that allow the user to manage or control the program and change
the settings to his preferences. The toolbar in the Microsoft Wordprogram, for instance, allows the user to change
the font type, size and color, as well as paragraph styles, formats and
referencing. It also has several other features for customization.
Taskbar
In a Windows operating
system, the taskbar is the horizontal bar that is visible at the bottom of the
screen. It was first introduced in Windows 95 and has been a part of
all subsequent releases of the operating system. The taskbar helps the user
locate and launch programs through the "Start" button, view programs
that are open, display or change the time/date, and view programs that are
functioning in the background.
Taskbar Sections
The taskbar has four
main sections: the Start button to open the start menu and launch programs; the
Quick Launch toolbar, which will help you start programs with a single click;
the Notification area on the extreme right, which
displays computer settings, date, time and status of some programs;
and the middle section, which shows the programs, documents, folders or files
that are open.
Differences
The taskbar is a part of
the operating system, while every different software or program has
its own taskbar. The taskbar has a set of fixed icons and functions. The
toolbar, on the other hand, can have different parts and functions depending on
the program. For instance, the Microsoft Word toolbar would have
controls for fonts and paragraphs while the one for Adobe Photoshop has controls for photo editing, including
colors, saturation, sharpening and blurs.
Q6.
Explain different loop structure in VB with example.
Visual Basic loop
structures allow you to run one or more lines of code repetitively. You can
repeat the statements in a loop structure until a condition is
True, until a condition
is False, a specified number of
times, or once for each element in a collection.
The following
illustration shows a loop structure that runs a set of statements until a
condition becomes true.
Running a set of statements until a condition becomes true
While Loops
The
While...End While construction runs a set of statements as long as the
condition specified in the Whilestatement is True. For more information, see While...End
While Statement.
Do Loops
The
Do...Loop construction allows you to test a condition at either the
beginning or the end of a loop structure. You can also specify whether to
repeat the loop while the condition remains True or until it becomes True. For more information, see Do...Loop
Statement.
For Loops
The
For...Next construction performs the loop a set number of times. It
uses a loop control variable, also called a counter, to keep track of the repetitions.
You specify the starting and ending values for this counter, and you can
optionally specify the amount by which it increases from one repetition to the
next. For more information, see For...Next
Statement.
For Each Loops
The
For Each...Next construction runs a set of statements
once for each element in a collection. You specify the loop control variable,
but you do not have to determine starting or ending values for it. For more
information, see For
Each...Next Statement.
Q7.
Write a program to calculate square of a given number.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim num1 As Integer
num1 = Val(TextBox1.Text)
TextBox2.Text = Math.Sqrt(num1)
End Sub
Q8. Write a program to create a simple calculator.
Public Class HesapMakinesi
Dim Firstnum As Decimal
Dim secondnum As Decimal
Dim Operations As Integer
Dim Operator_selctor As Boolean = False
Private Sub HesapMakinesi_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click
If Operator_selctor = True Then
secondnum = TextBox1.Text
If Operations = 1 Then
TextBox1.Text = Firstnum + secondnum
ElseIf Operations = 2 Then
TextBox1.Text = Firstnum - secondnum
ElseIf Operations = 3 Then
TextBox1.Text = Firstnum * secondnum
Else
If secondnum = 0 Then
TextBox1.Text = "Hata! Lütfen işleminizi kontrol edin."
Else
TextBox1.Text = Firstnum / secondnum
End If
End If
Operator_selctor = False
End If
End Sub
Private Sub Button15_Click(sender As Object, e As EventArgs) Handles Button15.Click
If TextBox1.Text <> "0" Then
TextBox1.Text += "1"
Else
TextBox1.Text = "1"
End If
End Sub
Private Sub Button10_Click(sender As Object, e As EventArgs) Handles Button10.Click
If TextBox1.Text <> "0" Then
TextBox1.Text += "2"
Else
TextBox1.Text = "2"
End If
End Sub
Private Sub Button6_Click(sender As Object, e As EventArgs) Handles Button6.Click
If TextBox1.Text <> "0" Then
TextBox1.Text += "3"
Else
TextBox1.Text = "3"
End If
End Sub
Private Sub Button16_Click(sender As Object, e As EventArgs) Handles Button16.Click
If TextBox1.Text <> "0" Then
TextBox1.Text += "4"
Else
TextBox1.Text = "4"
End If
End Sub
Private Sub Button13_Click(sender As Object, e As EventArgs) Handles Button13.Click
If TextBox1.Text <> "0" Then
TextBox1.Text += "5"
Else
TextBox1.Text = "5"
End If
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
If TextBox1.Text <> "0" Then
TextBox1.Text += "6"
Else
TextBox1.Text = "6"
End If
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
If TextBox1.Text <> "0" Then
TextBox1.Text += "7"
Else
TextBox1.Text = "7"
End If
End Sub
Private Sub Button17_Click(sender As Object, e As EventArgs) Handles Button17.Click
If TextBox1.Text <> "0" Then
TextBox1.Text += "8"
Else
TextBox1.Text = "8"
End If
End Sub
Private Sub Button12_Click(sender As Object, e As EventArgs) Handles Button12.Click
If TextBox1.Text <> "0" Then
TextBox1.Text += "9"
Else
TextBox1.Text = "9"
End If
End Sub
Private Sub Button14_Click(sender As Object, e As EventArgs) Handles Button14.Click
If TextBox1.Text <> "0" Then
TextBox1.Text += "0"
End If
End Sub
Private Sub Button8_Click(sender As Object, e As EventArgs) Handles Button8.Click
TextBox1.Text = "0"
End Sub
Private Sub Button3_Click(sender As Object, e As EventArgs) Handles Button3.Click
If Not (TextBox1.Text.Contains(".")) Then
TextBox1.Text += ","
End If
End Sub
Private Sub Button5_Click(sender As Object, e As EventArgs) Handles Button5.Click
Firstnum = TextBox1.Text
TextBox1.Text = ""
Operator_selctor = True
Operations = 1 ' = +
End Sub
Private Sub Button9_Click(sender As Object, e As EventArgs) Handles Button9.Click
Firstnum = TextBox1.Text
TextBox1.Text = ""
Operator_selctor = True
Operations = 2 ' - -
End Sub
Private Sub Button11_Click(sender As Object, e As EventArgs) Handles Button11.Click
Firstnum = TextBox1.Text
TextBox1.Text = ""
Operator_selctor = True
Operations = 3 '=x
End Sub
Private Sub Button7_Click(sender As Object, e As EventArgs) Handles Button7.Click
Firstnum = TextBox1.Text
TextBox1.Text = ""
Operator_selctor = True
Operations = 4 ' /
End Sub
Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
End Sub
End Class
Q9. Write a program to create a Notepad in VB.
Private Sub
Button1_Click(sender As Object, e As EventArgs)
Handles Button1.Click
Using fo As New OpenFileDialog
fo.Multiselect = False
fo.RestoreDirectory = True
fo.Filter = "Text Files|*.txt"
fo.FilterIndex = 1
fo.ShowDialog()
If (Not fo.FileName = Nothing) Then
TextBox1.Text =
File.ReadAllText(fo.FileName)
End If
End Using
End Sub
Private Sub
Button2_Click(sender As Object, e As EventArgs)
Handles Button2.Click
Using fs As New SaveFileDialog
fs.RestoreDirectory = True
fs.Filter = "Text Files|*.txt"
fs.FilterIndex = 1
fs.ShowDialog()
If Not (fs.FileName = Nothing) Then File.WriteAllText(fs.FileName, TextBox1.Text)
End Using
End Sub
End Class
Q10. Write a program to find factorial of a given number.
Private Sub Command1_Click()
Dim j, i as Integer
i = CInt(Text1.Text)
Label2.Caption = facts(i)
End Sub
Private Function facts(i)
F = 1
For j = 1 To i
F = F * j
facts = F
Next j
End Function
Q11. Write a program to calculate
the area of circle.
Dim
r, b, pi As Integer
Private Sub Command1_Click()
pi = 3.14
r = Text1.Text
b = pi * (r * r)
Label2.Caption = "The Area is " & b
End Sub
Private Sub Command3_Click()
Text1.Text = ""
Label2.Caption = ""
End Sub
Private Sub Command1_Click()
pi = 3.14
r = Text1.Text
b = pi * (r * r)
Label2.Caption = "The Area is " & b
End Sub
Private Sub Command3_Click()
Text1.Text = ""
Label2.Caption = ""
End Sub
Q12. Write a program to calculate
area of rectangle.
Public Class Form1
Private Sub txtLength_TextChanged(ByVal sender As Object, _
ByVal
e As System.EventArgs) Handles txtLength.TextChanged
Me.lblAreaAnswer.Text = ""
End
Sub
Private Sub txtWidth_TextChanged(ByVal sender As Object, _
ByVal e As
System.EventArgs) Handles txtWidth.TextChanged
Me.lblAreaAnswer.Text = ""
End
Sub
Private Sub radMultiplication_Click(ByVal sender As Object, _
ByVal
e As System.EventArgs) Handles btnAnswer.Click
Dim answer As Double
answer = Val(Me.txtLength.Text) * Val(Me.txtWidth.Text)
Me.lblAreaAnswer.Text = answer
End
Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
End
Sub
End Class
Q13. Write a program to calculate area of triangle.
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs)
Handles Button1.Click
TextBox2.Text = 3.14 * TextBox1.Text
End Sub
Private Sub Button2_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs)
Handles Button2.Click
TextBox5.Text = TextBox3.Text * TextBox4.Text
End Sub
Private Sub Button3_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs)
Handles Button3.Click
Dim a As Integer = TextBox6.Text
Dim b As Integer = TextBox7.Text
Dim c As Integer = TextBox8.Text
Dim s As Double = (a + b + c) / 2
Dim findarea As Double = Math.Sqrt(s * (s - a) * (s - b) *
(s - c))
TextBox9.Text = findarea
End Sub
End Class
Q14. Write a program to check whether the number is odd or
even.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim Mynumber As Integer
Dim isEven As Boolean
Mynumber = Val(TextBox1.Text)
If Mynumber Mod 2 = 0 Then
isEven = True
MsgBox("The
number " & "
" & Mynumber & "
is an even number")
Else
MsgBox(Mynumber & "
" & "is
an Odd number")
End If
End Sub
End Class
Q15. Write a program to find a
greatest number from 3 numbers.
Function calMax(x, y, z As Variant)
If x > y And x > z Then
calMax = Str(x)
ElseIf y > x And y > z Then
calMax = Str(y)
ElseIf z > x And z > y Then
calMax = Str(z)
End If
End Function
Private Sub Command1_Click()
Dim a, b, c
a = Val(Txt_Num1.Text)
b = Val(Txt_Num2.Text)
c = Val(Txt_Num3.Text)
Lbl_Display.Caption = calMax(a, b, c)
End Sub
Private Sub Label5_Click()
End Sub
If x > y And x > z Then
calMax = Str(x)
ElseIf y > x And y > z Then
calMax = Str(y)
ElseIf z > x And z > y Then
calMax = Str(z)
End If
End Function
Private Sub Command1_Click()
Dim a, b, c
a = Val(Txt_Num1.Text)
b = Val(Txt_Num2.Text)
c = Val(Txt_Num3.Text)
Lbl_Display.Caption = calMax(a, b, c)
End Sub
Private Sub Label5_Click()
End Sub
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