How to check if a string contains only numbers?

Dim number As String = "07747(a)"

If number.... Then

endif

I want to be able to check inside the string to see if it only has number, if it does only contain numbers then run whatever is inside the if statment? What check do i use to check if the string only contains numeric and no alpha ot 开发者_C百科() etc ..?

What i am trying to check for is mobile numbers, so 077 234 211 should be accepted, but other alphas should not be

You could use a regular expression like this

If Regex.IsMatch(number, "^[0-9 ]+$") Then

...

End If

Use IsNumeric Function :

IsNumeric(number)

If you want to validate a phone number you should use a regular expression, for example:

^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{3})$

http://msdn.microsoft.com/en-us/library/f02979c7(v=VS.90).aspx

You can pass nothing if you don't need the returned integer like so

if integer.TryParse(number,nothing) then

You may just remove all spaces and leverage LINQ All:

Determines whether all elements of a sequence satisfy a condition.

Use it as shown below:

Dim number As String = "077 234 211"
If number.Replace(" ", "").All(AddressOf Char.IsDigit) Then
    Console.WriteLine("The string is all numeric (spaces ignored)!")
Else
    Console.WriteLine("The string contains a char that is not numeric and space!")
End If

To only check if a string consists of only digits use:

If number.All(AddressOf Char.IsDigit) Then