Question

How to check if string is number in VB.NET

Answer 1

Imports System

Public Class Program
	Public Shared Sub Main()
        Dim str As String = "893"
        Dim n As Integer
		
        Dim isNumber As Boolean = Integer.TryParse(str, n)
		
        Console.WriteLine(isNumber)
        Console.WriteLine(n)
    End Sub
End Class




' run:
'
' True
' 893
'

 

70+ SQL courses for beginners and professionals

Answer 2

Imports System
Imports System.Text.RegularExpressions

Public Class Program
	Public Shared Sub Main()
        Dim str As String = "985"
        
		Dim isNumber = Regex.IsMatch(str, "^\d+$")
		
        Console.WriteLine(isNumber)
    End Sub
End Class





' run:
'
' True
'

 

70+ SQL courses for beginners and professionals

Answer 3

Imports System
Imports System.Linq

Public Class Program
    Public Shared Function IsNumeric(ByVal str As String) As Boolean
        Return str.All(AddressOf Char.IsNumber)
    End Function

    Public Shared Sub Main()
        Dim str As String = "891"
		
        Console.WriteLine(IsNumeric(str))
        Console.WriteLine(IsNumeric("15F"))
    End Sub
End Class






' run:
'
' True
' False
'

 

70+ SQL courses for beginners and professionals