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// Java
int[] arr = new int[5];
int[] arr2 = {10, 20, 30, 40, 50};

# Python
arr = [10, 20, 30, 40, 50]

// C++
int arr[5] = {10, 20, 30, 40, 50};

// JavaScript
const arr = [10, 20, 30, 40, 50];

Interactive Array Visualization

Rows (M)

Cols (N)

Normal

Shifting

Inserted/Updated

Removed

enhanced.realWorldExamples.title

SpotifyPlaylist Storage

Stores playlist tracks in arrays for O(1) random access when shuffling or jumping to specific songs.

Why? Arrays provide instant access to any track by position.

Game EnginesVertex Buffers

3D game engines store millions of vertex positions in arrays for GPU rendering.

Why? Contiguous memory layout matches GPU requirements.

Time Complexity

Understanding the efficiency of each operation helps you choose the right data structure for your needs.

Operation	Time	Why?
Create(M, N)	`O(M × N)`	Initialize all cells
Access (by index)	`O(1)`	Direct memory address calculation
Update (by index)	`O(1)`	Direct memory address calculation
Insert (at index)	`O(n)`	Shift elements to the right
Remove (at index)	`O(n)`	Shift elements to the left
Search (linear)	`O(n)`	May need to check every element
Traversal	`O(n)`	Visit each element once

Note: Where n = total number of elements (M × N for 2D arrays). Insert/Remove require shifting because arrays have fixed, contiguous memory allocation.

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Array access is O(1) because the memory address of any element can be calculated directly using the formula: address = base_address + (index × element_size). This single arithmetic operation executes in constant time regardless of array size.

🟢Best Case

Best case for access is O(1) - direct index lookup. Best case for search is O(1) when the element is at the first position.

🟡Average Case

Average case for linear search is O(n/2) which simplifies to O(n). For sorted arrays, binary search achieves O(log n).

🔴Worst Case

Worst case for insertion/deletion is O(n) when operating at the beginning, requiring all elements to shift.

💾Space Complexity

O(n) where n is the number of elements. Arrays have minimal overhead - just the element storage plus a small fixed header.

⚡Cache Performance

Excellent cache locality due to contiguous memory storage. Sequential access patterns achieve near-optimal CPU cache utilization.

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enhanced.codeWalkthrough.stepByStep

We first declare an array with a fixed size. In most languages, this allocates a contiguous block of memory to hold all elements. The size must be known at declaration time for static arrays.

// JavaScript
const arr = new Array(5);
// Creates array with 5 empty slots

enhanced.practiceProblems.title

Find Maximum Element

easy

Given an array of integers, find and return the maximum element.

Input:[3, 1, 4, 1, 5, 9, 2, 6]

Output:9

Reverse Array In-Place

easy

Reverse an array in-place without using extra space (except for a single temporary variable).

Input:[1, 2, 3, 4, 5]

Output:[5, 4, 3, 2, 1]

enhanced.relatedTopics.related

Linked List Stack Queue

enhanced.relatedTopics.advanced

Hash Table Heap

Continue Learning

Test your knowledge with a quiz or explore implementation code in multiple languages.

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enhanced.author.lastUpdated:January 26, 2026