Question

In an array declaration, there are two ways to specify the size of the array, one explicitly and one implicitly. Give the examples of both.

Answer 1

These are the current declaration and initialization methods for a simple array.

string[] array = new string[2]; // creates array of length 2, default values

string[] array = new string[] { "A", "B" }; // creates populated array of length 2

string[] array = { "A" , "B" }; // creates populated array of length 2

string[] array = new[] { "A", "B" }; // created populated array of length 2

Note that other techniques of obtaining arrays exist, such as the Linq ToArray() extensions on IEnumerable<T>.

Also note that in the declarations above, the first two could replace the string[] on the left with var (C# 3+), as the information on the right is enough to infer the proper type. The third line must be written as displayed, as array initialization syntax alone is not enough to satisfy the compiler's demands. The fourth could also use inference. So if you're into the whole brevity thing, the above could be written as

var array = new string[2]; // creates array of length 2, default values

var array = new string[] { "A", "B" }; // creates populated array of length 2

string[] array = { "A" , "B" }; // creates populated array of length 2

var array = new[] { "A", "B" }; //