Trim leading n alpha characters from string

Question

I need to trim the first n alpha characters from a string.

Examples:

a123456 -> 123456
abc123456 -> 123456
abc123456def -> 123456def

Thanks in advance for any help.

Answer 1

Try something like this:

String output = Regex.Replace(input, @"^[^\d]+", String.Empty);

Here is how the regular expression works:

^[^\d]+

^ anchors the expression to the beginning of the string
[^\d] is a character set matching all non-integral values
+ qualifies [^\d] by making it match one or more times

So basically this regular expression matches all non-integral characters in a string up until an integral character is found.

Answer 2

static string AlphaTrimRight(string value)
{
    while (!Char.IsNumber(value[0]))
        value = value.Substring(1, value.Length - 1);
    return value;
}