Difference between Stack and Array

The storing and arranging of data in a predefined format so that it can be retrieved and modified in efficient ways is one of the many things that you will want to accomplish, and Data Structures are the building blocks that make it possible. Data Structures are essentially logical representations of data that are used to store data in an ordered fashion in order to facilitate the execution of a variety of operations on the data.

Within a single computer programme, we have access to a variety of different ways to store and retrieve information. If you are using an object-oriented programming language, then "stacks" and "arrays" are the most frequent ways to store data. Using an array instead of a stack is certainly a valid implementation option. Access is the primary differentiating factor between the two options.

What is a Stack?

A stack is a type of data structure that is similar to a linear list and is represented by a sequential collection of objects.

  • A stack can be thought of as a physical stack or pile, in which the items are stacked one on top of the other like a stack of books. The objects are placed in such a way that it is only possible to add new items to or remove existing items from one end of the stack, which is referred to as the top of the stack.

  • A stack is a type of dynamic data structure whose size is always shifting due to the ongoing addition and removal of items from the stack.

  • The two most fundamental actions that may be carried out on a stack are known as push and pop. When you push items into a stack, they are added to it, and when you pop them off of a stack, they are removed from it.

  • Stacks adhere to a predetermined order that is known as LIFO, which stands for "last-in-first-out," and this means that the most recently added items are the ones that are removed from the stack first, followed by the item that was put first.

What is an Array?

An array is a form of linear data structure that is always defined as a collection of items that have the same data type.

  • The value of the array is always stored at a place that has been predetermined and is referred to as the array's index.

  • Arrays are not dynamic objects like stacks; rather, their sizes remain constant throughout their use. This means that once space is allocated for an array, its dimensions cannot be changed.

  • Arrays are one of the efficient techniques to carry out computations of the same kind on a number of components that all belong to the same data type.

  • Arrays can store one or more values that are of the same data type and allow access to those values using the indices that correspond to those values.

  • Arrays are a type of data structure that provide random access, which means that the items are stored in a linear fashion but can be accessed randomly.

Difference between Stack and Array

The following table highlights the major differences between a Stack and an Array −

Basis of comparisonStackArray
DefinitionA stack is a type of linear data structure that is represented by a collection of pieces that are arranged in a predetermined sequence.An array is a collection of data values that are associated to one another and termed elements. Each element is recognized by an indexed array.
MethodsPush, pop, and peek are the operations that one can perform on a stack.It has a wide range of techniques or operations that can be applied to it, such as sorting, traversing, going backward, push, pop, etc.
StorageThe size of a stack is dynamic.The size of an array is fixed.
PrincipleThe LIFO principle, which states that the element put last is the first to be removed from the list, is the foundation of stacks.If you wish to get into the fourth element of the array, for example, you will need to specify the variable name together with its index or location within the square brackets, such as "arr[4]". This is because the items in the array are assigned to indices.
Data AccessStacks do not permit arbitrary access to elements.In arrays, arbitrary access to elements is permitted.
OperationsWhen working with stacks, insertion and deletion can only take place from a single end of the list known as the top.Any position in the array's index can serve as the starting point for an insertion or deletion operation.
PointersIt just has one pointer, and it points to the top. This pointer specifies the address of the element that is now at the top of the stack, which is also the element that was most recently added.Memory can be allocated in arrays during build time, which is a process that is also referred to as static memory allocation.
ImplementationOne can create a stack using an array.Stacks cannot be used to implement an array.
Data TypesElements of several data kinds may be found in a stack.The items of an array are all of the same data type.


A stack is a basic representation of a collection of items in a data structure. The items in a stack are arranged in a specific order so that they can only be added to or removed from the stack from one end, which is the top of the stack in a LIFO or FILO order. Stacks can be either last-in-first-out (LIFO) or first-in-last-out (FILO) ordered.

In a static object known as an array, the number of components is always the same. In contrast to stacks, however, components of an array can have components added to or taken from it from either end, regardless of the order in which they were initially placed.

Updated on: 25-Jul-2022

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