How to use Array.reduce() method In Javascript

Q: How to use Array.reduce() method In Javascript

First, get the array of elements.Pass it to a function, which calls reduce() method on the array element.Return true if each element matches the first element of the array.

1. Using Array.every() method

3. Using Set

First, get the array of elements.
Pass it to a function, which calls reduce() method on the array element.
Return true if each element matches the first element of the array.

Example: This example uses an array.reduce() method to print the false for the given array.

Javascript

let arr = ["GFG", "GFG", "GFG", "GFG"];
function allEqual(arr) {
    if (!arr.length) return true;
    return arr.reduce(function (a, b) { 
           return (a === b) ? a : (!b); 
           }) === arr[0];
}
console.log(allEqual(arr));

Output

true

How to check all values of an array are equal or not in JavaScript ?

Ensuring all values in an array are equal is a common task in JavaScript, useful for validating data consistency and simplifying conditional checks. This guide provides an overview of efficient methods to determine if an array contains identical elements.

Below are the approaches used to check if all values of an array are equal or not in JavaScript: