Find Maximum

Problem Statement

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

Function Signature:

function findMax(arr) {
  // Your code here
}

Examples

Input	Output	Explanation
[3, 1, 4, 1, 5, 9, 2, 6]	9	9 is the largest value in the array
[-5, -2, -8, -1]	-1	-1 is the largest (least negative) value
[42]	42	Single element is the maximum
[7, 7, 7, 7]	7	All elements are equal

Constraints

• Array length: 1 ≤ arr.length ≤ 10,000
• Element values: -10⁹ ≤ arr[i] ≤ 10⁹
• Array is guaranteed to have at least one element

Interactive Editor

function findMax(arr) {
// Your code here

}

Tests: 6 total

Hints

Hint 1: The Approach

Track the largest value you've seen so far as you iterate. Compare each element to your current maximum and update when you find something larger.

Hint 2: Initialization

Initialize your maximum with arr[0], not 0. This handles negative numbers and single-element arrays correctly.

Solution

View Solution Explanation

function findMax(arr) {
  let max = arr[0];

  for (let i = 1; i < arr.length; i++) {
    if (arr[i] > max) {
      max = arr[i];
    }
  }

  return max;
}

Start with the first element as your maximum, then iterate through the rest. Update max whenever you find something larger.

Complexity: O(n) time, O(1) space.

Alternative: Math.max(...arr) works but can overflow the call stack on very large arrays.