string string1 = "Today is " + DateTime.Now.ToString("D") + ".";
Console.WriteLine(string1);
string string2 = "This is one sentence. " + "This is a second. ";
string2 += "This is a third sentence.";
Console.WriteLine(string2);
Method Name Description
ToLower() It is used to convert String into lowercase.
ToLowerInvariant() It is used to return convert String into lowercase using the casing rules of the invariant culture.
ToString() It is used to return instance of String.
ToUpper() It is used to convert String into uppercase.