Array vs. Pointer — What's the Difference?
By Tayyaba Rehman — Updated on September 20, 2023
An array is a collection of items stored at contiguous memory locations, while a pointer is a variable that stores the address of another variable.
Difference Between Array and Pointer
Table of Contents
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Key Differences
In the realm of programming, both arrays and pointers play pivotal roles, albeit with distinct functionalities. An array represents a collection of items, often of the same type, that are stored in contiguous memory locations. By employing an index, developers can swiftly access each individual item in the array. Contrarily, a pointer serves as a variable that specifically captures and stores the address of another variable within the memory.
Though closely related, arrays and pointers diverge in their primary usages. Arrays are preferred when one needs to group similar elements together, allowing for systematic storage and easy retrieval. Pointers, on the other hand, grant flexibility by letting programmers directly work with memory addresses, a feature invaluable for dynamic memory allocation and data structures like linked lists. Notably, the name of an array can be used as a pointer to its first element.
A notable distinction arises from their modifiability. While the size of an array, once defined, remains static, pointers can be shifted to point at different memory locations during execution. However, this adaptability of pointers calls for cautious handling; mishandled pointers can lead to various issues like memory leaks or segmentation faults.
In certain contexts, especially in languages like C and C++, arrays and pointers might seem interchangeable due to their close association with memory addresses. Yet, remembering their foundational differences is crucial. An array's name can be a pointer, but the array itself is a distinct memory block, whereas a pointer is a gateway to a memory location.
Comparison Chart
Nature
Collection of similar elements
Variable storing a memory address
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Memory Allocation
Contiguous
Stores address of any variable
Modifiability
Fixed size
Can point to different addresses
Usage
Storing related data elements
Dynamic memory allocation, referencing variables
Main Purpose
Organized data storage
Flexibility in memory reference
Compare with Definitions
Array
Collection of similar elements placed in contiguous memory locations.
The integer array contains five numbers.
Pointer
Variable that stores a memory address.
The pointer 'p' holds the address of variable 'x'.
Array
Fixed-size sequenced collection defined by a single name.
The 'days' array holds the names of all seven days of the week.
Pointer
Gateway to memory location allowing for flexible operations.
The pointer was reassigned to reference another variable.
Array
An array is a systematic arrangement of similar objects, usually in rows and columns.
Pointer
Essential tool for dynamic memory management in programming.
The pointer enabled us to allocate memory dynamically for the list.
Array
To set out for display or use; place in an orderly arrangement
Arrayed the whole regiment on the parade ground.
Pointer
Indirect data element access method via memory address.
The value was retrieved using the pointer's dereferencing operation.
Array
To dress, especially in fine clothes; adorn.
Pointer
A long tapered stick or a laser beacon used to call attention to objects, as on a chart or blackboard.
Array
An orderly, often imposing arrangement
An array of royal jewels.
Pointer
A scale indicator on a watch, balance, or other measuring instrument.
Array
An impressively large number, as of persons or objects
An array of heavily armed troops.
An array of spare parts.
Pointer
A dog of a breed developed in Europe to point game, having a smooth, short-haired coat that is often white with black or brownish markings.
Array
Splendid attire; fine clothing.
Pointer
A dog of any of various similar breeds.
Array
A rectangular arrangement of quantities in rows and columns, as in a matrix.
Pointer
A piece of advice; a suggestion
Let me give you a few pointers on your golf swing.
Array
Numerical data linearly ordered by magnitude.
Pointer
A piece of indicative information
Interest rates and other pointers in the economic forecast.
Array
An arrangement of usually identical devices, often sensors, that function as a unit
An array of solar panels.
Pointer
(Computers) A variable that holds the address of a core storage location.
Array
(Computers) A group of memory elements accessed by one or more indices.
Pointer
(Computers) A symbol appearing on a display screen in a GUI that lets the user select a command by clicking with a pointing device or pressing the enter key when the pointer symbol is positioned on the appropriate button or icon.
Array
Clothing and ornamentation.
Pointer
Either of the two stars in the Big Dipper, Dubhe and Merak, that are aligned so that a line drawn between them extends north to Polaris, the north star.
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.}}
Pointer
Anything that points or is used for pointing.
Array
A collection laid out to be viewed in full.
Pointer
A teacher's pointer, pointing stick, a rod with an arrow.
Array
An orderly series, arrangement or sequence.
Pointer
A needle-like component of a timepiece or measuring device that indicates the time or the current reading of the device.
Array
Order; a regular and imposing arrangement; disposition in regular lines; hence, order of battle.
Drawn up in battle array
Pointer
(hunting) A breed of hunting dog, trained to point out game.
Array
A large collection.
We offer a dazzling array of choices.
Pointer
(programming) A variable that holds the address of a memory location where a value can be stored.
Array
(mathematics) Common name for matrix.
Pointer
(graphical user interface) An icon that indicates the position of the pointing device, such as a mouse.
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.
Pointer
A tip, a bit of advice.
The instructor gave me some pointers on writing a good paper.
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.
Pointer
Something that gives a point sharp end to something.
Pencil pointer
Array
(military) A militia.
Pointer
(in combinations) Something worth a given number of points.
A ten-pointer
Array
A group of hedgehogs.
Pointer
One who, or that which, points.
Array
A microarray.
Pointer
A mark to indicate a direction or relation
Array
To clothe and ornament; to adorn or attire.
He was arrayed in his finest robes and jewels.
Pointer
An indicator as on a dial
Array
To lay out in an orderly arrangement; to deploy or marshal.
Pointer
(computer science) indicator consisting of a movable spot of light (an icon) on a visual display; moving the cursor allows the user to point to commands or screen positions
Array
(legal) To set in order, as a jury, for the trial of a cause; that is, to call them one at a time.
Pointer
A strong slender smooth-haired dog of Spanish origin having a white coat with brown or black patches; scents out and points game
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.
Pointer
Direct reference to another location in memory.
Using the pointer, we accessed the target data directly.
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.
Array
An imposing series of things.
Their long array of sapphire and of gold.
Array
Dress; garments disposed in order upon the person; rich or beautiful apparel.
Array
A ranking or setting forth in order, by the proper officer, of a jury as impaneled in a cause.
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.
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.
Array
To set in order, as a jury, for the trial of a cause; that is, to call them man by man.
Array
An orderly arrangement;
An array of troops in battle order
Array
An impressive display;
It was a bewildering array of books
His tools were in an orderly array on the basement wall
Array
Especially fine or decorative clothing
Array
An arrangement of aerials spaced to give desired directional characteristics
Array
Lay out in a line
Array
Align oneself with a group or a way of thinking
Array
Data structure holding more than one value at a time.
The array of characters forms a string.
Array
Indexed set allowing for systematic storage and retrieval.
By using an index, we retrieved the third element from the array.
Array
Homogeneous elements with a common name and different indexes.
The 'scores' array keeps track of every student's marks.
Common Curiosities
Can arrays and pointers be used interchangeably?
In some contexts, they can seem interchangeable, but they have fundamental differences.
Are the sizes of all pointers the same in a given system?
Typically, yes. Regardless of the datatype they point to, pointers usually have the same size on a specific system.
What is a null pointer?
A null pointer is a pointer that doesn't point to any valid memory location, usually denoted by 'NULL' or '0'.
Can the name of an array be used as a pointer?
Yes, an array's name can act as a pointer to its first element.
How are arrays indexed?
Arrays are usually zero-indexed, starting from 0 for the first element.
How can you find the length of an array?
The length can often be found using a size or length function, depending on the programming language.
Can an array's size be changed during execution?
No, an array has a fixed size once declared.
Can a pointer point to another pointer?
Yes, this is called a pointer to a pointer.
What happens if you dereference a null pointer?
Dereferencing a null pointer typically leads to undefined behavior, often resulting in a segmentation fault.
Is it possible to have an array of pointers?
Absolutely, arrays can contain pointer elements.
What's the significance of the 'address of' operator with pointers?
The 'address of' operator (&) fetches the memory address of a variable, which can be stored in a pointer.
Can pointers be used with non-array variables?
Yes, pointers can point to the address of any variable, not just arrays.
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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.
