The Reduce Method In JS

The Reduce Method In JS: Hello everyone, welcome to the nkcoderz.com website. In this article we will going to discuss about the The Reduce Method In JS.

Table of Contents

The reduce method in JavaScript is a built-in function on the Array object that allows you to apply a function to each element in the array and reduce it to a single value.

The function takes two arguments: an accumulator (which accumulates the result of the callback function) and the current value.

The reduce method can be used for tasks such as computing the sum of an array of numbers, concatenating an array of strings, or flattening an array of arrays.

Syntax:

array.reduce(function(accumulator, currentValue, currentIndex, array) {
  return accumulator;
}, initialValue);

Where:

function is the callback function that will be executed for each element in the array.
accumulator is the accumulator value that accumulates the result of the callback function.
currentValue is the current value being processed in the array.
currentIndex is the index of the current value being processed in the array.
array is the original array that reduce was called upon.
initialValue is the initial value of the accumulator. If not provided, the first element in the array will be used as the initial value.

Here’s an example of using the reduce method to calculate the sum of an array of numbers:

Reduce Method To Calculate The Sum Of An Array Of Numbers

let numbers = [1, 2, 3, 4, 5];

let sum = numbers.reduce(function(accumulator, currentValue) {
  return accumulator + currentValue;
}, 0);

console.log(sum);

Output

15

And here’s an example of using the reduce method to concatenate an array of strings:

Reduce Method To Concatenate An Array Of Strings

let words = ['Hello', 'World'];

let sentence = words.reduce(function(accumulator, currentValue) {
  return accumulator + ' ' + currentValue;
}, '');

console.log(sentence);

Output

'Hello World'

And finally, here’s an example of using the reduce method to flatten an array of arrays:

Reduce Method To Flatten An Array Of Arrays

let nestedArray = [[0, 1], [2, 3], [4, 5]];

let flattenArray = nestedArray.reduce(function(accumulator, currentValue) {
  return accumulator.concat(currentValue);
}, []);

console.log(flattenArray);

Output

[0, 1, 2, 3, 4, 5]

Conclusion

If you liked this post The Reduce Method In JS, then please share this with your friends and make sure to bookmark this website for more awesome content.