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Array vs. Structure: What's the Difference?

Edited by Aimie Carlson || By Harlon Moss || Updated on October 16, 2023
An array is a collection of elements of the same data type, while a structure is a collection of variables of different data types.

Key Differences

An array is a homogenous collection, meaning it holds multiple elements, but they all must be of the same type. A structure, on the other hand, is a composite data type that can store different types of variables within a single unit.
In programming, an array is typically used when you need a series of similar items like a list of numbers. Structure is used when you need a single entity with multiple attributes of varying types, like a record for an employee with a name, age, and salary.
Accessing an element in an array usually involves specifying a single index, such as array[5] for the sixth element. With a structure, individual members are accessed using dot notation, for example, employee.name or student.age.
Memory allocation for an array is contiguous, meaning all its elements are stored next to each other. In a structure, each member might be of a different size, but they are still grouped together under one label or name.
Both arrays and structures help in organizing data in programming. While arrays focus on providing a consistent set of similar data items, structures allow for more flexibility by combining different data types.

Comparison Chart

Basic Definition

Homogeneous collection.
Composite data type with different data types.


Store similar elements.
Store different attributes of a single entity.

Access Method

By index, e.g., array[3].
By member name, e.g., person.name.

Memory Allocation

Variable, based on member sizes.


Fixed to one data type for all elements.
Can contain different data types.

Array and Structure Definitions


A data structure in programming used to store collections of data.
Using an array made it easier to sort the data.


A data format in programming that allows combining data items of different types.
He used a structure to store information about each book.


An ordered arrangement or display.
She admired the beautiful array of flowers in the garden.


The arrangement of a set of ideas or an argument in a consistent order or form.
The essay had a clear and logical structure.


A list of items stored at specific accessible positions.
The array contained every student's ID number.


The arrangement of and relations between the parts or elements of something.
The building's structure was sound and robust.


A collection of similar items stored at contiguous memory locations.
The programmer used an array to store all the test scores.


The quality of being organized.
The structure of the event was meticulous and well-planned.


A large and impressive grouping or organization of things.
The soldiers stood in a vast array on the battlefield.


Something constructed or built, such as a building or bridge.
The Eiffel Tower is an iconic structure in Paris.


To set out for display or use; place in an orderly arrangement
Arrayed the whole regiment on the parade ground.


Something made up of a number of parts that are held or put together in a particular way
Hierarchical social structure.


To dress, especially in fine clothes; adorn.


The way in which parts are arranged or put together to form a whole; makeup
Triangular in structure.


What is a structure?

A structure is a composite data type in programming that can store different types of variables under one name.

What is an array?

An array is a collection of similar items stored at contiguous memory locations.

Can arrays grow dynamically?

Traditional arrays are of fixed size. However, some languages offer dynamic arrays or lists that can grow.

How is array different from structure?

An array stores elements of the same data type, while a structure can contain variables of different data types.

Why is memory allocation important for arrays?

Contiguous memory allocation ensures efficient access and manipulation of array elements.

Can arrays and structures be nested?

Yes, arrays can be inside structures, and structures can be inside other structures or arrays.

What is a two-dimensional array?

A two-dimensional array is like a table with rows and columns of elements.

Can structures contain functions?

In languages like C, structures typically hold data. In C++, however, structures can also have member functions.

What's the alternative to arrays in modern languages?

Modern languages offer lists, vectors, or dynamic arrays as flexible alternatives.

Can an array hold structures?

Yes, it's possible to have an array of structures.

How is memory allocated for a structure?

Memory for a structure is allocated based on the combined size of its members.

Why would one combine arrays and structures?

Combining them can help model complex data scenarios, like a database of student records, where each record is a structure, and the database is an array.

How do you access members in a structure?

Members in a structure are accessed using dot notation, like person.name.

How do you access elements in an array?

Elements in an array are accessed using an index, like array[2].

Are arrays always contiguous in memory?

Yes, arrays have contiguous memory allocation.

Can structures have arrays inside them?

Yes, structures can contain arrays as members.

Why would one use a structure over an array?

One would use a structure when needing to group different types of data under one entity, like a record.

Is a structure limited to a specific number of members?

No, a structure can have as many members as needed, limited only by memory constraints.

Are arrays and structures specific to a certain programming language?

No, most programming languages support both arrays and structures, but their implementation might vary.

How do structures help in object-oriented programming?

Structures can model real-world entities, laying the foundation for classes and objects in OOP.
About Author
Written by
Harlon Moss
Harlon is a seasoned quality moderator and accomplished content writer for Difference Wiki. An alumnus of the prestigious University of California, he earned his degree in Computer Science. Leveraging his academic background, Harlon brings a meticulous and informed perspective to his work, ensuring content accuracy and excellence.
Edited by
Aimie Carlson
Aimie Carlson, holding a master's degree in English literature, is a fervent English language enthusiast. She lends her writing talents to Difference Wiki, a prominent website that specializes in comparisons, offering readers insightful analyses that both captivate and inform.

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