VB.Net Tutorial/Data Type/Integer — различия между версиями
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Версия 19:40, 26 мая 2010
Содержание
- 1 Add two integers together
- 2 Compare Integer value in If statement
- 3 Define Integer variable and assign value
- 4 Explicit conversion of an integer to a string
- 5 Implicit conversion of an integer to a string
- 6 Integer boolean calculation: Or, And, Xor, Not
- 7 Integer calculation
- 8 Integer format: D10
- 9 Integer.GetType
- 10 Integer OverflowException
- 11 MinValue and MaxValue of Integer
- 12 Parse Integer
- 13 Parse Integer variable and get hash code from Integer
- 14 Pass Integer to a function by reference
- 15 Pass Integer to a function by value
- 16 Swap two integers without using a third
- 17 Use Integer.CompareTo to compare two integers
Add two integers together
<source lang="vbnet">Module Tester
Sub Main() Dim firstNumber, secondNumber As String Dim number1, number2, sumOfNumbers As Integer firstNumber = 10 secondNumber = 20 number1 = firstNumber number2 = secondNumber sumOfNumbers = number1 + number2 " add numbers Console.WriteLine("The sum is {0}", sumOfNumbers) End Sub " Main
End Module</source>
The sum is 30
Compare Integer value in If statement
<source lang="vbnet">Module Module1
Sub Main() Dim TestScore As Integer = 80 If TestScore >= 90 Then Console.WriteLine("Test grade: A") ElseIf TestScore >= 80 Then Console.WriteLine("Test grade: B") ElseIf TestScore >= 70 Then Console.WriteLine("Test grade: C") Else Console.WriteLine("Test grade: F") End If End Sub
End Module</source>
Test grade: B
Define Integer variable and assign value
<source lang="vbnet">Module Module1
Sub Main( ) Dim myInt As Integer = 7 Console.WriteLine("Initialized myInt: {0}", myInt) myInt = 5 Console.WriteLine("After assignment myInt: {0}", myInt) End Sub End Module</source>
Initialized myInt: 7 After assignment myInt: 5
Explicit conversion of an integer to a string
<source lang="vbnet">Module Tester
Public Sub Main() Dim iInteger As Integer = 5280 Dim lLong As Long Dim bytByte As Byte Dim sngSingle As Single Dim dblDouble As Double Dim decDecimal As Decimal Console.WriteLine("Explicit conversion of an integer to a string: {0}", CStr(iInteger)) End Sub
End Module</source>
Explicit conversion of an integer to a string: 5280
Implicit conversion of an integer to a string
<source lang="vbnet">Module Tester
Public Sub Main() Dim iInteger As Integer = 5280 Dim lLong As Long Dim bytByte As Byte Dim sngSingle As Single Dim dblDouble As Double Dim decDecimal As Decimal Console.WriteLine("Implicit conversion of an integer to a string: {0}", iInteger) End Sub
End Module</source>
Implicit conversion of an integer to a string: 5280
Integer boolean calculation: Or, And, Xor, Not
<source lang="vbnet">public class Test
public Shared Sub Main Dim I As Integer I = 3 Or 4 Console.WriteLine(I) I = 2 And 4 Console.WriteLine(I) I = 3 Xor 3 Console.WriteLine(I) I = Not 5 Console.WriteLine(I) End Sub
End class</source>
7 0 0 -6
Integer calculation
<source lang="vbnet">public class Test
public Shared Sub Main Dim n As Integer " try adding numbers... n = 16 n += 10.23 Console.WriteLine("Addition " & n) " try subtracting numbers... n = 24 n -= 2 Console.WriteLine("Subtraction " & n) " try multiplying numbers... n = 6 n *= 10 Console.WriteLine("Multiplication " & n) " try dividing numbers... n = 12 n /= 6 Console.WriteLine("Division " & n)
End Sub
End class</source>
Addition 26 Subtraction 22 Multiplication 60 Division 2
Integer format: D10
<source lang="vbnet">Public Class Tester
Public Shared Sub Main Dim intNumber As Integer = 12345 Console.WriteLine(intNumber.ToString("D10")) End Sub
End Class</source>
0000012345
Integer.GetType
<source lang="vbnet">Module Module1
Const x As String = "This is a string" Sub Main() Dim a As Double = 5.678 Dim b As Int32 = 123 Console.WriteLine(a.ToString) Console.WriteLine(b.ToString) Console.WriteLine(456.987.ToString) Dim c As Integer Console.WriteLine(c.GetType()) Console.WriteLine(c.GetType().ToString) End Sub
End Module</source>
5.678 123 456.987 System.Int32 System.Int32
Integer OverflowException
<source lang="vbnet">Public Class Tester
Public Shared Sub Main Dim A, B As Integer Dim C As Integer Try A = 9999 B = 9999 C = A * B * B * B Catch Except As OverflowException Console.WriteLine("Overflow error detected") End Try End Sub
End Class</source>
Overflow error detected
MinValue and MaxValue of Integer
<source lang="vbnet">public class Test
public Shared Sub Main Dim iNum As Integer Console.WriteLine("Integer: " & iNum.MinValue & " to " & iNum.MaxValue) End Sub
End class</source>
Integer: -2147483648 to 2147483647
Parse Integer
<source lang="vbnet">public class Test
public Shared Sub Main Try Dim num_items As Integer = Integer.Parse("123") Catch ex As Exception Console.WriteLine(ex.Message) End Try End Sub
End class</source>
Parse Integer variable and get hash code from Integer
<source lang="vbnet">public class Test
public Shared Sub Main Dim Number As String Number = "4" Console.WriteLine(Integer.Parse(Number)) Console.WriteLine(Number.GetHashCode()) End Sub
End class</source>
4 -842352756
Pass Integer to a function by reference
<source lang="vbnet">Module Module1
Sub ParameterChange(ByRef A As Integer) A = 1001 Console.WriteLine("Value of A in subroutine " & A) End Sub Sub Main() Dim Number As Integer = 100 Console.WriteLine("Number before function call: " & Number) ParameterChange(Number) Console.WriteLine("Number before function call: " & Number) End Sub
End Module</source>
Number before function call: 100 Value of A in subroutine 1001 Number before function call: 1001
Pass Integer to a function by value
<source lang="vbnet">Module Module1
Sub NoChangeToParameter(ByVal A As Integer) A = 1001 Console.WriteLine("Value of A in subroutine " & A) End Sub Sub Main() Dim Number As Integer = 100 Console.WriteLine("Number before function call: " & Number) NoChangeToParameter(Number) Console.WriteLine("Number before function call: " & Number) End Sub
End Module</source>
Number before function call: 100 Value of A in subroutine 1001 Number before function call: 100
Swap two integers without using a third
<source lang="vbnet">Imports System.Drawing Imports System.Drawing.Drawing2D Imports System.Collections Public Class Tester
Public Shared Sub Main Dim firstValue As Integer Dim secondValue As Integer firstValue = 17 secondValue = 123 Console.WriteLine("Before swap: {0}, {1}",firstValue, secondValue) firstValue = firstValue Xor secondValue secondValue = firstValue Xor secondValue firstValue = firstValue Xor secondValue Console.WriteLine("After swap: {0}, {1}",firstValue, secondValue) End Sub
End Class</source>
Before swap: 17, 123 After swap: 123, 17
Use Integer.CompareTo to compare two integers
<source lang="vbnet">public class Test
public Shared Sub Main Dim I As Integer = 0 Dim S As Integer = 8 Console.WriteLine(I.rupareTo(S)) End Sub
End class</source>
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