Returns true if the given string can be parsed into an integer, false otherwise.

  • Return the result of calling Double.TryParse() with NymberStyles.Integer for the given num string.
  • Use Double.TryParse() to allow handling of values larger than Int64.
using System.Globalization;

public static partial class _30s 
  public static bool IsInteger(string num) 
    Double _ = 0.0;
    return Double.TryParse(num, NumberStyles.Integer, NumberFormatInfo.CurrentInfo, out _);
_30s.IsInteger("2"); // true
_30s.IsInteger("3.1"); // false