FizzBuzz

Print numbers 1 to n, replacing multiples of 3 with 'Fizz', multiples of 5 with 'Buzz', and multiples of both with 'FizzBuzz'.

Problem Overview

The Ultimate Pattern Recognition Test

FizzBuzz is the quintessential programming interview question that tests your ability to handle multiple conditions elegantly. Count from 1 to n, but with a twist - numbers divisible by specific values get replaced with words!

🧠 The Logic Challenge:

Divisible by 3: Replace with "Fizz"
Divisible by 5: Replace with "Buzz"
Divisible by both: Replace with "FizzBuzz" (order matters!)
Everything else: Keep the original number as string
Three Implementation Strategies:
Standard If-Else: Clear, readable, checks 15 first for efficiency
String Concatenation: Elegant approach that builds the result dynamically
Functional One-Liner: Array.from + ternary operators for concise code
Real-World Applications:
Rule Engines: Business logic with multiple conditional branches
Data Transformation: Converting numeric data based on business rules
Game Logic: Implementing scoring systems with special conditions
Report Generation: Formatting data with conditional text replacement

💡 Learning Value:

Conditional logic and operator precedence
Modulo arithmetic for divisibility testing
String vs numeric data handling
Code clarity vs cleverness trade-offs

Concepts

LoopsConditionalsModular Arithmetic

Complexity Analysis

Time:O(n)

Space:O(n)

Performance Notes:

- Time: O(n) - must process each number once - Space: O(n) - output array grows with input size

Solutions

fizzBuzz

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

export function fizzBuzz(n: number): string[] {
  if (!Number.isInteger(n) || n < 1) throw new Error("Input must be a positive integer");
  const result: string[] = [];
  for (let i = 1; i <= n; i++) {
    if (i % 15 === 0) result.push("FizzBuzz");
    else if (i % 3 === 0) result.push("Fizz");
    else if (i % 5 === 0) result.push("Buzz");
    else result.push(i.toString());
  }
  return result;
}

Examples & Test Cases

#1Classic FizzBuzz up to 15

Input:15

Output:

[
  "1",
  "2",
  "Fizz",
  "4",
  "Buzz",
  "Fizz",
  "7",
  "8",
  "Fizz",
  "Buzz",
  "11",
  "Fizz",
  "13",
  "14",
  "FizzBuzz"
]

#2Small example

Input:5

Output:

[
  "1",
  "2",
  "Fizz",
  "4",
  "Buzz"
]

#3Invalid input

Input:0

Output:{}