IsLower

Checks if a string is lower case.

• Convert the given string to lower case, using string.ToLower() and compare it to the original.

public static partial class _30s 
{
  public static bool IsLower(string str) 
  {
    return str.ToLower() == str;
  }
}

string s1 = "abc";
string s2 = "cDe";

_30s.IsLower(s1); // true
_30s.IsLower(s2); // false