Unity List Length

Unity – Get list length?

To retrieve the length of a list in Unity, use the Count property: int length = myList.Count;

Here’s a concrete example:

var myList = new List<int>() { 5, 4, 3, 2, 1 };
int length = myList.Count;

In C# and Unity, the Length property is used for arrays, while for lists, the Count property should be used.

For further information on lists, please consult : Unity List Collection: A Comprehensive Guide

Using LINQ Method

It’s also possible to use LINQ to retrieve the length of a list by using the extension method Count.

However, it’s not recommended due to potential performance issues as it may resort to enumeration if the Count property is not available.

What to do with the length of a list?

The length of a list can be utilized for various purposes.

The most common use is to iterate through the elements of a list using a for loop.
For example:

var myList = new List<int>() { 5, 4, 3, 2, 1 };
for (int i = 0; i < myList.Count; i++)
{
    int number = myList[i];
}

Tips: Instantiate a list with known length

For better performance, when instantiating a list with a known length, it’s advisable to set the capacity explicitly.

This can be done by passing an integer to the list constructor, like this: var myList = new List<int>(50);

Indeed, when the list reaches its maximum capacity, it has to be resized to accommodate more elements, which may mean copying all existing elements to a new memory area.
This can be costly in terms of performance, especially if the list undergoes numerous add operations.