JavaScript Program to Find Largest Element in an Array

In this article, we are going to learn about the largest element in an array in JavaScript. The largest element in an array refers to the value that holds the greatest numerical or lexicographic (string) order among all elements present in the array.

Example:

Input : [10, 15, 38, 20, 13];
Output: 38
Here we will see the 38 is the largest elements in the given array.

Several methods can be used to find the largest Element in an Array in Javascript, which are listed below:

Using the reduce() Method

In this approach, Using the reduce() method, iterate through the array while comparing elements. Accumulate the largest element by updating the accumulator if the current element is greater. Return the largest element.

Syntax:

array.reduce( function(total, currentValue, currentIndex, arr), initialValue );

Example: In this approach, we are using the above-explained approach.

function largestElement(arr) {
    return arr.reduce((largest, current) =>
        (current > largest ? current : largest), arr[0]);
}

let num1 = [10, 15, 38, 20, 13];
console.log(largestElement(num1)); 

38

Using the Spread Operator and Math.max() Method

In this approach, the spread operator (...) with Math.max(), directly pass array elements as arguments, allowing the method to find and return the largest element in the array.

Syntax:

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

Example: In this example, we are using the Spread Operator and Math.max() to find the largest number from our given array.

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

const num1 = [10, 15, 28, 20, 13];
const result = largestElement(num1);

console.log("The largest element in the array is:" + result); 

The largest element in the array is:28

Using for Loop

In this approach, Using a for loop, iterate through the array, comparing each element to a running largest value, updating it if a larger element is encountered, and returning the final largest value.

Syntax:

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

Example: In this approach, we are using for loop to find the largest number from our given array.

function largestElement(arr) {
    let largestNum = arr[0];
    for (let i = 1; i < arr.length; i++) {
        if (arr[i] > largestNum) {
            largestNum = arr[i];
        }
    }
    return largestNum;
}

const num1 = [10, 15, 18, 20, 23];
const result = largestElement(num1);

console.log("The largest element in the array is:" + result); 

The largest element in the array is:23

Using the sort() method

In this approach we apply sort() method to array which will sort the array in ascending order. After sorting the largest element will be at the end of the array. We will return the last element which will be the largest element.

Syntax:

arr.sort((a, b) => a - b);
largestElement = arr[arr.length - 1];

Example: In this approach, we are using sort() method to find the largest number from our given array.

function findLargest(arr) {

    arr.sort((a, b) => a - b); // Sort the array in ascending order
    return arr[arr.length - 1]; // Return the last element
}

let arr = [10, 5, 20, 8];
console.log("Largest element in the array is:", findLargest(arr));

Largest element in the array is: 20

Using a ForEach Loop

Using a forEach loop iterates through the array, updating the largest element encountered. It initializes the largest element with the first element, then compares each subsequent element, updating the largest value accordingly.

Example

const array = [10, 5, 20, 8, 15];
let largest = array[0];

array.forEach(element => {
    if (element > largest) {
        largest = element;
    }
});

console.log("Largest element:", largest);

Largest element: 20