Showing posts with label map. Show all posts
Showing posts with label map. Show all posts

Wednesday, June 7, 2017

Array Map, Filter, Reduce methods (Array mfr in short)

Use map when you want to change each value in the array based on some logic

var mappedArray = [2,4].map(number => number * 2)

console.log(mappedArray)


Use filter when you want filter out some values from an array based on some logic

var filteredArray = [1,2,3,4].filter(number => (number % 2 === 0))

console.log(filteredArray)


Use reduce when you want to reduce an array into a single resulting value

var reducedArray = [1,2,3,4].reduce((total,number) => total + number, 0)

console.log(reducedArray)

Cute reference: https://medium.com/@joshpitzalis/the-trouble-with-loops-f639e3cc52d9