Identify if a string is a number

Question

If I have these strings:

1. \"abc\" = false

2. \"123\" = true

3. \"ab2\"

Answer 1

Use these extension methods to clearly distinguish between a check if the string is numerical and if the string only contains 0-9 digits

public static class ExtensionMethods
{
    /// 

    /// Returns true if string could represent a valid number, including decimals and local culture symbols
    /// 
    public static bool IsNumeric(this string s)
    {
        decimal d;
        return decimal.TryParse(s, System.Globalization.NumberStyles.Any, System.Globalization.CultureInfo.CurrentCulture, out d);
    }

    /// 

    /// Returns true only if string is wholy comprised of numerical digits
    /// 
    public static bool IsNumbersOnly(this string s)
    {
        if (s == null || s == string.Empty)
            return false;

        foreach (char c in s)
        {
            if (c < '0' || c > '9') // Avoid using .IsDigit or .IsNumeric as they will return true for other characters
                return false;
        }

        return true;
    }
}