How to define Array in C#

Please pick a book or search Google/Online material before asking such basic questions.
Start from here:
MSDN: Arrays Tutorial[^]
C# String Arrays[^]

Various ways:

// various ways
string[] arr1 = new string[] { "one", "two", "three" };

string[] arr2 = { "one", "two", "three" };

var arr3 = new string[] { "one", "two", "three" };

string[] arr4 = new string[3];
arr4[0] = "one";
arr4[1] = "two";
arr4[2] = "three";