C# List vs. C# Array — What's the Difference?
By Tayyaba Rehman — Published on January 4, 2024
A C# List is a dynamic array with automatic resizing, while a C# Array is a fixed-size collection of elements of the same type.
Difference Between C# List and C# Array
Table of Contents
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Key Differences
A C# List is a collection class defined in the System.Collections.Generic namespace. It represents a list of objects that can be accessed by index and provides methods to search, sort, and manipulate lists. On the other hand, a C# Array is a data structure that contains a fixed number of elements of a particular type, also accessible by index.
In a C# List, the size is dynamically adjusted as elements are added or removed, which means there is no need to define the size at the start. Conversely, a C# Array has a fixed size, and the number of elements it can hold must be specified at the time of its declaration.
C# List provides a range of useful methods such as Add(), Remove(), Find(), and Sort(), that facilitate dynamic list manipulation. The C# Array, while not as flexible, is more performant for fixed-size collections and offers a lower-level control of the data structure which can be beneficial for performance-critical applications.
Memory allocation in a C# List is handled internally, and it grows automatically as the collection grows. Arrays in C#, however, are allocated with a fixed amount of memory, and if a larger collection is needed, a new array must be created and the elements copied to the new array.
C# Lists are part of the newer, generic collections designed to be more flexible and provide type safety without the need for casting. Arrays are a more basic form of collection that have been in the language since its inception and are supported by the runtime at a very low level, making them slightly faster than a List for certain operations.
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Comparison Chart
Size
Dynamic size
Fixed size
Namespace
System.Collections.Generic
System
Performance
Slower for larger lists
Faster for fixed-size, static collections
Memory Allocation
Automatically resized
Size defined at declaration, not resized
Methods
Add, Remove, Find, Sort, etc.
Length, CopyTo, Clone, etc.
Type Safety
Strongly-typed, generic
Strongly-typed, non-generic
Compare with Definitions
C# List
A generic collection that can grow and shrink dynamically.
I used a C# List to store user inputs because its size can change.
C# Array
Must have its size defined upon declaration.
When declaring the Array, I specified it should hold ten elements.
C# List
Ensures type safety and eliminates the need for casting.
The List only allows integer values, ensuring type safety.
C# Array
A fixed-size collection of elements that can be indexed.
I created a C# Array of integers to store fixed data.
C# List
Can be sorted and manipulated with LINQ queries.
Sorting the List was simple with the Sort() method.
C# Array
Can be multi-dimensional for complex data structures.
Multi-dimensional arrays are great for matrix operations.
C# List
Does not require a predefined size at compile time.
I initialized the List without specifying how many elements it would hold.
C# Array
Is the basis for many other collection types in C#.
Arrays underpin many more complex data structures in C#.
C# List
Provides methods to add, remove, and search items.
The List's Add() method made it easy to append new items.
C# Array
Provides fast access and performance for static data sets.
Array indexing allowed me to quickly access elements.
Common Curiosities
What is a C# Array?
A C# Array is a fixed-size collection of elements of the same type.
Can C# Lists store different types?
No, C# Lists are generic but each instance stores one type of elements.
Can you resize a C# Array?
No, C# Arrays cannot be resized without creating a new array and copying elements.
What is a C# List?
A C# List is a dynamically sized, generic collection of elements.
How do you iterate over a C# List?
You can use a for loop or foreach loop to iterate over a C# List.
How do you initialize a C# Array?
A C# Array is initialized with a specified size and optionally initial values.
Can you create multi-dimensional Lists in C#?
Not directly, but you can have a List of Lists to simulate multi-dimensionality.
When should you use a C# List over an Array?
Use a C# List when you need a collection that can change in size.
How do you find an element in a C# Array?
Use methods like Array.Find() or a loop to search for elements.
Are C# Arrays faster than Lists?
Arrays can be faster due to their fixed size and direct memory access.
How do you add items to a C# List?
Use the Add() method to append items to a C# List.
What is the capacity of a C# List?
The capacity of a List is the number of elements it can hold before needing to resize. It grows automatically as required.
Do C# Lists guarantee ordering?
Yes, C# Lists maintain the order of elements as they are added.
How do you remove an item from a C# List?
Use the Remove() or RemoveAt() methods to remove items from a List.
Can you sort a C# Array?
Yes, you can use the Array.Sort() method to sort an array.
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Written by
Tayyaba RehmanTayyaba Rehman is a distinguished writer, currently serving as a primary contributor to askdifference.com. As a researcher in semantics and etymology, Tayyaba's passion for the complexity of languages and their distinctions has found a perfect home on the platform. Tayyaba delves into the intricacies of language, distinguishing between commonly confused words and phrases, thereby providing clarity for readers worldwide.
