VB.Net Tutorial/Data Type/Double
Содержание
- 1 Convert Double to Integer
- 2 Declare Double type variable and assign value
- 3 Define and loop through double value array
- 4 Define double and output its value
- 5 Double.IsNaN()
- 6 Double.IsNegativeInfinity()
- 7 Double.IsPositiveInfinity()
- 8 Get Epsilon from Double
- 9 Parse Double
- 10 Parse double value
- 11 Read Double value from Keyboard
Convert Double to Integer
<source lang="vbnet">Module Module1
Sub Main() Dim dblValue As Double Dim intValue As Integer dblValue = 1.2345678 intValue = dblValue Console.WriteLine(intValue) End Sub
End Module</source>
1
Declare Double type variable and assign value
<source lang="vbnet">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</source>
Number of employees: 1 Employee name: James Bond Employee phone number: 555-1212 Employee salary: 45
Define and loop through double value array
<source lang="vbnet">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</source>
100 200 300 400 500 25.5 4.95 33.4
Define double and output its value
<source lang="vbnet">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</source>
10 3.33333333333333
Double.IsNaN()
<source lang="vbnet">Imports System Module MyModule
Sub Main() If (Double.IsNaN("1.2")) Then Console.WriteLine("Not a Number.") End If End Sub
End Module</source>
Double.IsNegativeInfinity()
<source lang="vbnet">Imports System Module MyModule
Sub Main() If (Double.IsNegativeInfinity("0.0000000000000001")) Then Console.WriteLine("Negative infinity.") End If End Sub
End Module</source>
Double.IsPositiveInfinity()
<source lang="vbnet">Imports System Module MyModule
Sub Main() If (Double.IsPositiveInfinity("999999999999999999999999999999999")) Then Console.WriteLine("Positive infinity.") End If End Sub
End Module</source>
Get Epsilon from Double
<source lang="vbnet">public class Test
public Shared Sub Main Dim D As Double D = 5 Console.WriteLine(D.Epsilon) End Sub
End class</source>
4.94065645841247E-324
Parse Double
<source lang="vbnet">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</source>
5.50909090909091
Parse double value
<source lang="vbnet">Public Class Tester
Public Shared Sub Main Dim doubleParse As Double = Double.Parse("3.1416") Console.WriteLine(doubleParse) End Sub
End Class</source>
3.1416
Read Double value from Keyboard
<source lang="vbnet">Module Module1
Sub Main() Dim Salary As Double Console.Write("Salary: ") Salary = Console.ReadLine() Console.WriteLine(Salary) End Sub
End Module</source>
Salary: 123 123