Array vs. Arraylist: Know the Difference
By Shumaila Saeed || Published on February 22, 2024
An Array is a fixed-size, indexed collection of elements of the same type, while an ArrayList is a dynamic-size, indexed collection in Java that can grow and shrink.
Key Differences
An Array in programming is a data structure consisting of a collection of elements, each identified by an array index. The size of an Array is fixed upon its creation. Conversely, an ArrayList is a resizable array implementation in the Java programming language, part of the Java Collections Framework.
Shumaila Saeed
Feb 22, 2024
Arrays can hold primitive data types or objects, but the type must be uniform and declared at the time of array creation. ArrayLists, on the other hand, can only hold objects and not primitive types, automatically converting primitive types to objects via boxing.
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Feb 22, 2024
Memory allocation for an Array is static and continuous, meaning the memory size allocated for the array cannot be changed once declared. An ArrayList dynamically allocates memory, allowing it to increase or decrease its size as elements are added or removed.
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Feb 22, 2024
In terms of performance, accessing elements in an Array is faster due to direct indexing. However, ArrayLists offer more flexibility with methods for adding, removing, and manipulating data, though these operations can be slower compared to Arrays due to dynamic resizing and memory allocation.
Shumaila Saeed
Feb 22, 2024
Arrays are a basic structure in many programming languages, while ArrayLists are specific to Java. ArrayLists provide more functionality, like the ability to easily check if it contains a certain element, which requires manual implementation in an Array.
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Feb 22, 2024
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Comparison Chart
Performance
Faster access, simpler structure
More flexible, but potentially slower access
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Feb 22, 2024
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Array and Arraylist Definitions
Array
A collection of elements of the same type, stored in contiguous memory locations.
He accessed the third element of the integer array by using array[2].
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Jan 22, 2024
Arraylist
Allows dynamic size modification.
As more items were added, the ArrayList expanded automatically.
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Jan 22, 2024
Array
A basic building block in programming that uses indexing.
For the loop, each array element was accessed sequentially by its index.
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Jan 22, 2024
Arraylist
Part of the Java Collections Framework.
The ArrayList was preferred for its collection manipulation methods.
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Jan 22, 2024
Array
Requires size specification at the time of declaration.
He declared an array of doubles with a size of 5.
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Jan 22, 2024
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Arraylist
A resizable array implementation in Java.
She used an ArrayList to dynamically store the growing list of participants.
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Jan 22, 2024
Array
To set out for display or use; place in an orderly arrangement
Arrayed the whole regiment on the parade ground.
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Jan 19, 2024
Arraylist
Only holds objects, converting primitives to objects automatically.
The ArrayList of integers automatically boxed the primitive int values.
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Jan 22, 2024
Arraylist
Provides methods for easy manipulation of data.
He removed an element from the ArrayList using the remove method.
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Jan 22, 2024
Array
An impressively large number, as of persons or objects
An array of heavily armed troops.
An array of spare parts.
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Jan 19, 2024
Array
A rectangular arrangement of quantities in rows and columns, as in a matrix.
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Jan 19, 2024
Array
An arrangement of usually identical devices, often sensors, that function as a unit
An array of solar panels.
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Jan 19, 2024
Array
(Computers) A group of memory elements accessed by one or more indices.
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Jan 19, 2024
Array
7, Laws N21|url=http://www.joe-offer.com/folkinfo/songs/129.html|passage=Sovay, Sovay all on a day, She dressed herself in man's array, With a sword and a pistol all by her side, To meet her true love to meet her true love away did ride.}}
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Jan 19, 2024
Array
Order; a regular and imposing arrangement; disposition in regular lines; hence, order of battle.
Drawn up in battle array
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Jan 19, 2024
Array
(programming) Any of various data structures designed to hold multiple elements of the same type; especially, a data structure that holds these elements in adjacent memory locations so that they may be retrieved using numeric indices.
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Jan 19, 2024
Array
(legal) A ranking or setting forth in order, by the proper officer, of a jury as impanelled in a cause; the panel itself; or the whole body of jurors summoned to attend the court.
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Jan 19, 2024
Array
To clothe and ornament; to adorn or attire.
He was arrayed in his finest robes and jewels.
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Jan 19, 2024
Array
(legal) To set in order, as a jury, for the trial of a cause; that is, to call them one at a time.
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Jan 19, 2024
Array
Order; a regular and imposing arrangement; disposition in regular lines; hence, order of battle; as, drawn up in battle array.
Wedged together in the closest array.
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Jan 19, 2024
Array
The whole body of persons thus placed in order; an orderly collection; hence, a body of soldiers.
A gallant array of nobles and cavaliers.
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Jan 19, 2024
Array
An imposing series of things.
Their long array of sapphire and of gold.
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Jan 19, 2024
Array
Dress; garments disposed in order upon the person; rich or beautiful apparel.
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Jan 19, 2024
Array
A ranking or setting forth in order, by the proper officer, of a jury as impaneled in a cause.
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Jan 19, 2024
Array
To place or dispose in order, as troops for battle; to marshal.
By torch and trumpet fast arrayed,Each horseman drew his battle blade.
These doubts will be arrayed before their minds.
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Jan 19, 2024
Array
To deck or dress; to adorn with dress; to cloth to envelop; - applied esp. to dress of a splendid kind.
Pharaoh . . . arrayed him in vestures of fine linen.
In gelid caves with horrid gloom arrayed.
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Jan 19, 2024
Array
To set in order, as a jury, for the trial of a cause; that is, to call them man by man.
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Jan 19, 2024
Array
An impressive display;
It was a bewildering array of books
His tools were in an orderly array on the basement wall
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Jan 19, 2024
Array
An arrangement of aerials spaced to give desired directional characteristics
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Jan 19, 2024
Array
A fixed-size data structure.
The array of size 10 could not store more than 10 elements.
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Jan 22, 2024
Array
Can store either primitives or objects, depending on the declaration.
The string array contained different names as its elements.
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Jan 22, 2024
Repeatedly Asked Queries
What is an Array?
A fixed-size collection of elements of the same type, stored in contiguous memory.
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Feb 22, 2024
How is memory allocated for an Array?
Memory is allocated statically and continuously.
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Feb 22, 2024
Can an Array hold different data types?
No, it must hold elements of a declared, uniform type.
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Feb 22, 2024
How do you access elements in an Array?
Using direct indexing, like array[index].
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Feb 22, 2024
Can an ArrayList hold primitive types?
It holds objects, but auto-boxes primitive types to their wrapper classes.
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Feb 22, 2024
Can you mix Arrays and ArrayLists in code?
Yes, but you may need to convert between them.
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Feb 22, 2024
How are elements accessed in an ArrayList?
Typically with get and set methods, like arrayList.get(index).
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Feb 22, 2024
Why would you use an ArrayList over an Array?
For flexibility in size and more built-in methods.
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Feb 22, 2024
Are there any disadvantages to using an ArrayList?
It can be slower and uses more memory than an Array.
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Feb 22, 2024
Are Arrays specific to Java?
No, they are a basic structure in many programming languages.
Shumaila Saeed
Feb 22, 2024
Is an Array faster than an ArrayList?
Generally yes, especially for indexed access.
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Feb 22, 2024
What operations can you perform on an ArrayList?
Adding, removing, and manipulating elements, among others.
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Feb 22, 2024
How do you initialize an ArrayList?
With new ArrayList<>(), optionally setting initial capacity.
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Feb 22, 2024
Is ArrayList unique to Java?
Yes, it's part of Java's Collections Framework.
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Feb 22, 2024
How do you initialize an Array?
By specifying its size and type at declaration.
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Feb 22, 2024
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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.
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