如何删除所有alpha的字符串？

Question

Dim phoneNumber As String = "077 47578 587(num)"

如何从每个不是数字的字符上删除上面的字符串.所以只留下数字,然后检查以确保它长11个字符？

Answer 1

dim number as string = Regex.Replace(phoneNumber,"[^0-9]","")

if number.length = 11 then
 'valid number
else
 'not valid
end if