How to check if a string contains only numbers

Question

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

User · Accepted Answer

You could use a regular expression like this   If Regex IsMatch number     0-9       Then       End If

User · Answer

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

User · Answer

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

User · Answer

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

[vb.net] How to check if a string contains only numbers?

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