Structure vs. Union: Know the Difference
By Shumaila Saeed || Updated on December 25, 2023
A structure in programming allocates separate memory for each of its members, while a union uses the same memory location for all its members.
Key Differences
In programming, a structure is a data type that allows the storage of different data types under one name. Each member within a structure has its own memory location. A union, on the other hand, also stores different data types but uses a single shared memory location for all its members, storing only one member at a time.
Shumaila Saeed
Nov 18, 2023
The size of a structure is determined by the total sum of the sizes of its members. It represents the total memory required to store all members. In contrast, the size of a union is determined by the size of its largest member, as it can only hold one member at a time in the shared memory space.
Shumaila Saeed
Nov 18, 2023
When a structure is used, accessing each member is independent of the others as each has a unique memory location. This allows for different members to be accessed and modified simultaneously. In a union, since all members share the same memory location, modifying one member can alter the values of others.
Shumaila Saeed
Nov 18, 2023
Structures are typically used when storing multiple distinct data items that need to be accessed independently, such as different attributes of an object. Unions are useful in situations where only one of several data items is required at a time, allowing for memory-efficient storage.
Shumaila Saeed
Nov 18, 2023
In summary, structures offer a way to group different data types with independent memory allocations for each member, providing flexibility and independent access. Unions, while similar in syntax, focus on memory efficiency by overlapping the storage of its members, suitable for specialized use cases where only one member is used at a time.
Shumaila Saeed
Nov 18, 2023
ADVERTISEMENT
Comparison Chart
Memory Allocation
Allocates separate memory for each member.
Shares the same memory location for all members.
Shumaila Saeed
Nov 18, 2023
Size Determination
Size equals the sum of all member sizes.
Size equals the size of the largest member.
Shumaila Saeed
Nov 18, 2023
Member Accessibility
Independent access to each member.
Only one member can be used at a time.
Shumaila Saeed
Nov 18, 2023
Usage Scenario
For storing multiple distinct data items.
For storing one of several data items at a time.
Shumaila Saeed
Nov 18, 2023
Modification Impact
Modifying one member does not affect others.
Modifying one member can alter others.
Shumaila Saeed
Nov 18, 2023
ADVERTISEMENT
Structure and Union Definitions
Structure
An arrangement or organization of parts to form an object.
The Eiffel Tower is known for its intricate metal structure.
Shumaila Saeed
Nov 15, 2023
Union
The act of being united or joined.
The union of these two companies will create a market leader.
Shumaila Saeed
Nov 15, 2023
Structure
A complex system considered from the point of view of the whole rather than of any single part.
The social structure of the community was very inclusive.
Shumaila Saeed
Nov 15, 2023
Union
In programming, a data type allowing the storage of different data types in the same memory location.
We used a union to efficiently manage memory in our software.
Shumaila Saeed
Nov 15, 2023
Structure
The quality of being organized.
She admired the structure of the well-planned garden.
Shumaila Saeed
Nov 15, 2023
ADVERTISEMENT
Structure
The way in which parts are arranged or put together to form a whole.
The structure of the novel was unique and engaging.
Shumaila Saeed
Nov 15, 2023
Union
A combination so formed, especially an alliance or confederation of people, parties, or political entities for mutual interest or benefit.
Shumaila Saeed
Oct 19, 2023
Structure
Something made up of a number of parts that are held or put together in a particular way
Hierarchical social structure.
Shumaila Saeed
Oct 19, 2023
Union
(Mathematics) A set, every member of which is an element of one or another of two or more given sets.
Shumaila Saeed
Oct 19, 2023
Structure
The way in which parts are arranged or put together to form a whole; makeup
Triangular in structure.
Shumaila Saeed
Oct 19, 2023
Union
Agreement or harmony resulting from the uniting of individuals; concord.
Shumaila Saeed
Oct 19, 2023
Structure
The interrelation or arrangement of parts in a complex entity
Political structure.
Plot structure.
Shumaila Saeed
Oct 19, 2023
Union
The state of matrimony; marriage
"The element that was to make possible such a union was trust in each other's love" (Kate Chopin).
Shumaila Saeed
Oct 19, 2023
Structure
The arrangement or formation of the tissues, organs, or other parts of an organism.
Shumaila Saeed
Oct 19, 2023
Union
A combination of parishes for joint administration of relief for the poor in Great Britain.
Shumaila Saeed
Oct 19, 2023
Structure
To give form or arrangement to
Structure a curriculum.
Structure one's day.
Shumaila Saeed
Oct 19, 2023
Structure
A cohesive whole built up of distinct parts.
The birds had built an amazing structure out of sticks and various discarded items.
Shumaila Saeed
Oct 19, 2023
Structure
The underlying shape of a solid.
He studied the structure of her face.
Shumaila Saeed
Oct 19, 2023
Union
A device on a flag or ensign, occupying the upper inner corner or the entire field, that signifies the union of two or more sovereignties.
Shumaila Saeed
Oct 19, 2023
Structure
The overall form or organization of something.
The structure of a sentence.
The structure of the society was still a mystery.
Shumaila Saeed
Oct 19, 2023
Union
An organization at a college or university that provides facilities for recreation; a student union.
Shumaila Saeed
Oct 19, 2023
Structure
A set of rules defining behaviour.
For some, the structure of school life was oppressive.
Shumaila Saeed
Oct 19, 2023
Structure
(computing) Several pieces of data treated as a unit.
This structure contains both date and timezone information.
Shumaila Saeed
Oct 19, 2023
Union
Union The United States of America regarded as a national unit, especially during the Civil War.
Shumaila Saeed
Oct 19, 2023
Structure
Underwater terrain or objects (such as a dead tree or a submerged car) that tend to attract fish
There's lots of structure to be fished along the west shore of the lake; the impoundment submerged a town there when it was built.
Shumaila Saeed
Oct 19, 2023
Union
Union Of, relating to, or loyal to the United States of America during the Civil War
A Union soldier.
Shumaila Saeed
Oct 19, 2023
Structure
A body, such as a political party, with a cohesive purpose or outlook.
The South African leader went off to consult with the structures.
Shumaila Saeed
Oct 19, 2023
Union
Of or relating to a labor union or labor union organizing
The union movement.
Union negotiations.
Shumaila Saeed
Oct 19, 2023
Structure
(logic) A set along with a collection of finitary functions and relations.
Shumaila Saeed
Oct 19, 2023
Union
(countable) The act of uniting or joining two or more things into one.
Shumaila Saeed
Oct 19, 2023
Structure
(transitive) To give structure to; to arrange.
I'm trying to structure my time better so I'm not always late.
I've structured the deal to limit the amount of money we can lose.
Shumaila Saeed
Oct 19, 2023
Union
(countable) The state of being united or joined; a state of unity or harmony.
Shumaila Saeed
Oct 19, 2023
Structure
The act of building; the practice of erecting buildings; construction.
His son builds on, and never is contentTill the last farthing is in structure spent.
Shumaila Saeed
Oct 19, 2023
Union
(countable) That which is united, or made one; something formed by a combination or coalition of parts or members; a confederation; a consolidated body; a league.
Shumaila Saeed
Oct 19, 2023
Structure
Manner of building; form; make; construction.
Want of insight into the structure and constitution of the terraqueous globe.
Shumaila Saeed
Oct 19, 2023
Structure
Arrangement of parts, of organs, or of constituent particles, in a substance or body; as, the structure of a rock or a mineral; the structure of a sentence.
It [basalt] has often a prismatic structure.
Shumaila Saeed
Oct 19, 2023
Union
(countable) An association of students at a university for social and/or political purposes; also in some cases a debating body.
Shumaila Saeed
Oct 19, 2023
Structure
Manner of organization; the arrangement of the different tissues or parts of animal and vegetable organisms; as, organic structure, or the structure of animals and plants; cellular structure.
Shumaila Saeed
Oct 19, 2023
Union
(countable) A joint or other connection uniting parts of machinery, such as pipes.
Shumaila Saeed
Oct 19, 2023
Structure
That which is built; a building; esp., a building of some size or magnificence; an edifice.
There stands a structure of majestic frame.
Shumaila Saeed
Oct 19, 2023
Structure
A thing constructed; a complex construction or entity;
The structure consisted of a series of arches
She wore her hair in an amazing construction of whirls and ribbons
Shumaila Saeed
Oct 19, 2023
Structure
The manner of construction of something and the arrangement of its parts;
Artists must study the structure of the human body
The structure of the benzene molecule
Shumaila Saeed
Oct 19, 2023
Structure
The complex composition of knowledge as elements and their combinations;
His lectures have no structure
Shumaila Saeed
Oct 19, 2023
Union
A data structure that can store any of various types of item, but only one at a time.
Shumaila Saeed
Oct 19, 2023
Structure
A particular complex anatomical structure;
He has good bone structure
Shumaila Saeed
Oct 19, 2023
Structure
The people in a society considered as a system organized by a characteristic pattern of relationships;
The social organization of England and America is very different
Sociologists have studied the changing structure of the family
Shumaila Saeed
Oct 19, 2023
Union
(historical) An affiliation of several parishes for joint support and management of their poor; also the jointly-owned workhouse.
Shumaila Saeed
Oct 19, 2023
Structure
In programming, a data structure consisting of a group of elements.
We used a structure to store various data types in our code.
Shumaila Saeed
Nov 15, 2023
Union
Belonging to, represented by, or otherwise pertaining to a labour union.
Actors have to be union to get work here.
Shumaila Saeed
Oct 19, 2023
Union
The act of uniting or joining two or more things into one, or the state of being united or joined; junction; coalition; combination.
Shumaila Saeed
Oct 19, 2023
Union
Agreement and conjunction of mind, spirit, will, affections, or the like; harmony; concord.
Shumaila Saeed
Oct 19, 2023
Union
That which is united, or made one; something formed by a combination or coalition of parts or members; a confederation; a consolidated body; a league; as, the weavers have formed a union; trades unions have become very numerous; the United States of America are often called the Union.
Shumaila Saeed
Oct 19, 2023
Union
A textile fabric composed of two or more materials, as cotton, silk, wool, etc., woven together.
Shumaila Saeed
Oct 19, 2023
Union
A large, fine pearl.
If they [pearls] be white, great, round, smooth, and weighty . . . our dainties and delicates here at Rome . . . call them unions, as a man would say "singular," and by themselves alone.
In the cup an union shall he throw,Richer than that which four successive kingsIn Denmark's crown have worn.
Shumaila Saeed
Oct 19, 2023
Union
A device emblematic of union, used on a national flag or ensign, sometimes, as in the military standard of Great Britain, covering the whole field; sometimes, as in the flag of the United States, and the English naval and marine flag, occupying the upper inner corner, the rest of the flag being called the fly. Also, a flag having such a device; especially, the flag of Great Britain.
Shumaila Saeed
Oct 19, 2023
Union
A joint or other connection uniting parts of machinery, or the like, as the elastic pipe of a tender connecting it with the feed pipe of a locomotive engine; especially, a pipe fitting for connecting pipes, or pipes and fittings, in such a way as to facilitate disconnection.
Shumaila Saeed
Oct 19, 2023
Union
A cask suspended on trunnions, in which fermentation is carried on.
One kingdom, joy, and union without end.
[Man] is to . . . begetLike of his like, his image multiplied.In unity defective; which requiresCollateral love, and dearest amity.
Shumaila Saeed
Oct 19, 2023
Union
An organization of employees formed to bargain with the employer;
You have to join the union in order to get a job
Shumaila Saeed
Oct 19, 2023
Union
The United States (especially the northern states during the American Civil War);
He has visited every state in the Union
Lee hoped to detach Maryland from the Union
The North's superior resources turned the scale
Shumaila Saeed
Oct 19, 2023
Union
The act of pairing a male and female for reproductive purposes;
The casual couplings of adolescents
The mating of some species occurs only in the spring
Shumaila Saeed
Oct 19, 2023
Union
The state of being joined or united or linked;
There is strength in union
Shumaila Saeed
Oct 19, 2023
Union
The state of being a married couple voluntarily joined for life (or until divorce);
A long and happy marriage
God bless this union
Shumaila Saeed
Oct 19, 2023
Union
Healing process involving the growing together of the edges of a wound or the growing together of broken bones
Shumaila Saeed
Oct 19, 2023
Union
A political unit formed from previously independent people or organizations;
The Soviet Union
Shumaila Saeed
Oct 19, 2023
Union
A set containing all and only the members of two or more given sets;
Let C be the union of the sets A and B
Shumaila Saeed
Oct 19, 2023
Union
The occurrence of a uniting of separate parts;
Lightning produced an unusual union of the metals
Shumaila Saeed
Oct 19, 2023
Union
A device on a national flag emblematic of the union of two or more sovereignties (typically in the upper inner corner)
Shumaila Saeed
Oct 19, 2023
Union
The act of making or becoming a single unit;
The union of opposing factions
He looked forward to the unification of his family for the holidays
Shumaila Saeed
Oct 19, 2023
Union
Being of or having to do with the northern United States and those loyal to the Union during the Civil War;
Union soldiers
Federal forces
A Federal infantryman
Shumaila Saeed
Oct 19, 2023
Union
Of trade unions;
The union movement
Union negotiations
A union-shop clause in the contract
Shumaila Saeed
Oct 19, 2023
Union
The act of joining two or more things into one.
The union of the two rivers created a beautiful delta.
Shumaila Saeed
Nov 15, 2023
Union
A state of harmony or agreement.
They were in union on the decision to move forward.
Shumaila Saeed
Nov 15, 2023
Union
An organized association of workers formed to protect and further their rights and interests.
The workers formed a union to negotiate better terms.
Shumaila Saeed
Nov 15, 2023
Repeatedly Asked Queries
What is the primary use of a union in programming?
A union is primarily used to save memory by efficiently storing one of several data types at a time.
Shumaila Saeed
Nov 18, 2023
How does a union differ from a structure in terms of memory?
A union uses the same memory location for all its members, unlike a structure which allocates separate memory for each member.
Shumaila Saeed
Nov 18, 2023
What happens when you modify a member of a union?
Modifying a member of a union can change the values of other members since they share memory space.
Shumaila Saeed
Nov 18, 2023
What is the main advantage of using a union?
The main advantage of using a union is its memory efficiency, as it uses the same memory for different members.
Shumaila Saeed
Nov 18, 2023
Can a structure contain multiple data types?
Yes, a structure can contain multiple data types, each as a separate member.
Shumaila Saeed
Nov 18, 2023
What is a structure in programming?
A structure is a user-defined data type in programming that groups different data types under one name.
Shumaila Saeed
Nov 18, 2023
How is the size of a structure determined?
The size of a structure is the sum of the sizes of all its members.
Shumaila Saeed
Nov 18, 2023
Can unions have methods in programming?
No, unions in programming are used for storage and don't have methods.
Shumaila Saeed
Nov 18, 2023
Is it possible for a union and a structure to have the same members?
Yes, both can have the same types of members, but they handle them differently in memory.
Shumaila Saeed
Nov 18, 2023
Can structures be nested in programming?
Yes, structures can be nested within other structures.
Shumaila Saeed
Nov 18, 2023
Are structures in programming similar to classes?
Structures are similar to classes but lack features like methods and access specifiers.
Shumaila Saeed
Nov 18, 2023
How does memory alignment work in structures?
In structures, each member is aligned in memory according to its data type.
Shumaila Saeed
Nov 18, 2023
What distinguishes a structure's functionality from a union's?
A structure allows independent access and storage of multiple data types, while a union focuses on memory efficiency by overlapping these data types.
Shumaila Saeed
Nov 18, 2023
What is a typical scenario for using a structure?
Structures are typically used when there is a need to group different data types and access them independently.
Shumaila Saeed
Nov 18, 2023
What is the impact of modifying a structure's member?
Modifying a member of a structure does not affect the other members.
Shumaila Saeed
Nov 18, 2023
How is the size of a union calculated?
The size of a union is determined by its largest member.
Shumaila Saeed
Nov 18, 2023
Are arrays allowed in structures?
Yes, arrays can be used as members of structures.
Shumaila Saeed
Nov 18, 2023
Can a union contain a structure?
Yes, a union can contain a structure as one of its members.
Shumaila Saeed
Nov 18, 2023
Can a union be used to store different data types simultaneously?
No, a union can only store one data type at a time in its shared memory space.
Shumaila Saeed
Nov 18, 2023
Is it possible to initialize a structure at the time of declaration?
Yes, structures can be initialized at the time of declaration in programming.
Shumaila Saeed
Nov 18, 2023
Share this page
Link for your blog / website
HTML
Link to share via messenger
About Author
Written by
Shumaila SaeedShumaila Saeed, an expert content creator with 6 years of experience, specializes in distilling complex topics into easily digestible comparisons, shining a light on the nuances that both inform and educate readers with clarity and accuracy.
Shumaila Saeed
Hifza Nasir
