Reverse a String

Reverses a string, returning the characters in opposite order

Problem Overview

📝 The Text Processing Building Block
String reversal is a fundamental text manipulation operation that appears in countless programming scenarios! From palindrome checking to cryptography, this simple operation forms the foundation for more complex string algorithms.

🧠 The Reversal Challenge:

Character Order: Transform "abc" → "cba" by reversing character sequence
Preserve Content: All characters remain, only order changes
Handle Edge Cases: Empty strings, single characters, special symbols
Memory Consideration: Balance between simplicity and efficiency
Two Classic Approaches:
Built-in Methods: Leverage JavaScript's split/reverse/join - concise and readable
Manual Loop: Character-by-character reversal - educational and explicit
Real-World Applications:
Palindrome Detection: Check if text reads the same forwards and backwards
Cryptography: Simple text obfuscation and encoding schemes
Data Processing: Reversing sequences in data transformation pipelines
Algorithm Building: Foundation for more complex string manipulation
Text Effects: Creating mirror text for UI animations and effects

💡 Learning Value:

String immutability concepts in JavaScript
Array manipulation and method chaining
Loop design and index management
Trade-offs between readability and performance

Concepts

string manipulationarray iterationbuilt-in methods

Complexity Analysis

Time:O(n)

Space:O(n)

Performance Notes:

- Time: O(n) - must process every character once - Space: O(n) - creating new string with same length

Solutions

reverseString

Time: O(n) | Space: O(n)

export function reverseString(str: string): string {
  if (typeof str !== 'string') throw new Error("Input must be a string");
  return str.split('').reverse().join('');
}

Examples & Test Cases

#1Basic reversal

Input:hello

Output:olleh

#2Empty string

Input:

Output:

#3Single character

Input:a

Output:a

#4Numeric string

Input:12345

Output:54321

#5Special characters

Input:!@#

Output:#@!

#6With spaces

Input:Hello World

Output:dlroW olleH