JavaScript Interview Questions For Beginners - ES6

Q. What is JavaScript Array reduce() method?
A. In Javascript ES6, reduce method is used to perform some operation on each array element. Below is the syntax:

let numbers = [1, 2, 3];

let sum = numbers.reduce(function (accumulator, currentValue) {
    return accumulator + currentValue;
});
console.log(sum);

Output:

6

Here, we are adding all elements in the array and saving its result in sum variable. Each variable details:

• numbers: is a array variable
• sum: is the result of adding each element in array
• accumulator: indicates the previous element value in the loop
• currentValue: is the value of current element