VB.Net Tutorial/Data Type/Double

Материал из VB Эксперт
Версия от 12:54, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
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Convert Double to Integer

Module Module1
    Sub Main()
        Dim dblValue As Double
        Dim intValue As Integer
        dblValue = 1.2345678
        intValue = dblValue
        Console.WriteLine(intValue)
    End Sub
End Module
1

Declare Double type variable and assign value

Module Module1
    Sub Main()
        Dim EmployeeName As String
        Dim EmployeePhoneNumber As String
        Dim EmployeeSalary As Double
        Dim NumberOfEmployees As Integer
        EmployeeName = "James Bond"
        EmployeePhoneNumber = "555-1212"
        EmployeeSalary = 45.0
        NumberOfEmployees = 1
        Console.WriteLine("Number of employees: " & NumberOfEmployees)
        Console.WriteLine("Employee name: " & EmployeeName)
        Console.WriteLine("Employee phone number: " & EmployeePhoneNumber)
        Console.WriteLine("Employee salary: " & EmployeeSalary)
    End Sub
End Module
Number of employees: 1
Employee name: James Bond
Employee phone number: 555-1212
Employee salary: 45

Define and loop through double value array

Module Tester
    Sub Main()
        Dim Values() As Integer = {100, 200, 300, 400, 500}
        Dim MyValues(5) As Integer
        Dim Prices() As Double = {25.5, 4.95, 33.4}
        Dim I As Integer
        For I = 0 To 4
            Console.Write(Values(I) & " ")
        Next
        Console.WriteLine()
        For I = 0 To Prices.GetUpperBound(0)
            Console.Write(Prices(I) & " ")
        Next
    End Sub
End Module
100 200 300 400 500
25.5 4.95 33.4

Define double and output its value

public class Test
   public Shared Sub Main
        Dim I As Integer = 2
        I *= 5
        Console.WriteLine(I)
    
        Dim D As Double = I / 3
        Console.WriteLine(D)
   End Sub
End class
10
3.33333333333333

Double.IsNaN()

Imports System                
Module MyModule
  Sub Main()
    If (Double.IsNaN("1.2")) Then
      Console.WriteLine("Not a Number.")
    End If
  End Sub
End Module

Double.IsNegativeInfinity()

Imports System                
Module MyModule
  Sub Main()
    If (Double.IsNegativeInfinity("0.0000000000000001")) Then
        Console.WriteLine("Negative infinity.")
    End If
  End Sub
End Module

Double.IsPositiveInfinity()

Imports System                
Module MyModule
  Sub Main()
    If (Double.IsPositiveInfinity("999999999999999999999999999999999")) Then
      Console.WriteLine("Positive infinity.")
    End If
  End Sub
End Module

Get Epsilon from Double

public class Test
   public Shared Sub Main
        Dim D As Double
    
        D = 5
        Console.WriteLine(D.Epsilon)
   End Sub
End class
4.94065645841247E-324

Parse Double

Imports System                
Module MyModule
  Sub Main()
    Dim num As Double = Double.Parse("12.12")
    Dim denom As Double = Double.Parse("2.2")
    Dim res As Double = num / denom
    Console.WriteLine(res)
  End Sub
End Module
5.50909090909091

Parse double value

Public Class Tester
    Public Shared Sub Main
        Dim doubleParse As Double = Double.Parse("3.1416")
        Console.WriteLine(doubleParse)
    End Sub

End Class
3.1416

Read Double value from Keyboard

Module Module1
    Sub Main()
        Dim Salary As Double
        Console.Write("Salary: ")
        Salary = Console.ReadLine()
        Console.WriteLine(Salary)
    End Sub
End Module
Salary: 123
123