readme.md

Challenge: Find Max Number

Instructions

Write a function called findMaxNumber that takes in an array of numbers and returns the largest number in the array.

Function Signature

/**
 * Returns the largest number in an array.
 * @param {number[]} arr - The array of numbers.
 * @returns {number} - The largest number in the array.
 */
function findMaxNumber(arr: number[]): number;

Examples

findMaxNumber([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]); // 10
findMaxNumber([10, 9, 8, 7, 6, 5, 4, 3, 2, 1]); // 10
findMaxNumber([1, 2, 3, 4, 5, 10, 9, 8, 7, 6]); // 10

Hints

• There is a very easy way to do this using a specific built-in method. I would suggest not doing it that way. Try to solve this problem using a for loop.

Solutions

Click For Solution 1

This is the easy way to do it. There is a method called Math.max() that will return the largest number in an array. This is not the way I would suggest doing it, but it is good to know that this method exists.

function findMaxNumber(arr) {
  return Math.max(...arr);
}

Explanation

There is not too much explanation needed here.

Click For Solution 2

Here is another way of solving it using a for loop.

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

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

  return max;
}

Explanation

• Create a variable called max and setting it equal to the first element in the array.
• Loop through the array starting at the second element.
• Check if the current element is greater than the current value of max. If it is, we set max equal to the current element.
• Return max after the loop is finished.

Test Cases

test('Finding the maximum number in an array', () => {
  expect(findMaxNumber([1, 5, 3, 9, 2])).toBe(9);
  expect(findMaxNumber([0, -1, -5, 2])).toBe(2);
  expect(findMaxNumber([10, 10, 10, 10])).toBe(10);
});