Functional Programming in Javascript

Functional Programming in Javascript


Code - Functional programming (FP) - Collection Operations in javascript.

All functional programming functions are array operations - See Doc


To get the cookies

console.log("Functional Programming: The cookies that we see with Javascript");

    .map(cookie => cookie.split("="))



All function returns an array.

A few returns an element such as:

  • find: returns the value of the first element in the provided array that satisfies the provided testing function.
  • findIndex() method returns the index of the first element in the array that satisfies the provided testing function.


Javascript - Map function (Functional programming)

Map example 1

data = [
  { name: 'Nicolas', firstname: 'Gerard', surname: 'nico' },
  { name: 'Rixt', firstname: 'Van Der Veen', surname: 'konigin' }

names = function (d) { return } )

firstnames = function (d) { return d.firstname } )

surnames = function (d) { return d.surname } )

Map example 2 - select and process

var myList = []'selector')) (element) {
  // ....


filter functional programming function.

Example a split on a string that does contains a separator without value create an empty string element. We filter it below.

let s = "aStringWithoutSeparator.";

console.log("With filtering");
console.log( s.split ('.').filter(el => {return el.length != 0}));

console.log("Without filtering");
console.log(s.split ('.'))


terminal function are all array function that does not produce an array such as:

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