Question

Is it possible to create an empty array without specifying the size?

For example, I created:

String[] a = new String[5];

Can we create the above string array without the size?

Answer 1

If you are going to use a collection that you don’t know the size of in advance, there are better options than arrays.

Use a List<string> instead – it will allow you to add as many items as you need and if you need to return an array, call ToArray() on the variable.

var listOfStrings = new List<string>();

// do stuff...

string[] arrayOfStrings = listOfStrings.ToArray();

If you must create an empty array you can do this:

string[] emptyStringArray = new string[0]; 

As of .NET 4.6, the following would be recommended for an empty array:

String[] a = Array.Empty<string>();

With C# 12/.NET8, there’s an even more succinct way (using collection expressions):

String[] a = [];