JAVASCRIPT

Arrow functions in ES6

let func = (a) => {}         // parentheses optional with one parameter
let func = (a, b, c) => {} // parentheses required with multiple parameters

Arrow Functions

// The usual way of writing function
const magic = function() {
  return new Date();
};

// Arrow function syntax is used to rewrite the function
const magic = () => {
  return new Date();
};
//or
const magic = () => new Date();

Arrow functions in js

/**
I think that you might be looking for 
the js "arrow function"; I hope that 
this example below helps ;)
**/ 

// usual function
function fartOne(){
    console.log('Pooofff... pof.. ppf.. poof.. p');
}

// arrow function to do the same
const fartTwo = () => console.log('Baaaf... paf.. poof.. poffie.. plop');

// call the functions to test 'em out..
fartOne();
fartTwo();

how to write an arrow function in javascript?

function double(x) { return x * 2; } // Traditional way
console.log(double(2)) // 4


const double = x => x * 2; // Same function written as an arrow function with implicit return
console.log(double(2)) // 4

arrow functions=>

// Traditional Anonymous Function
function (a, b){
  return a + b + 100;
}

// Arrow Function
(a, b) => a + b + 100;

// Traditional Anonymous Function (no arguments)
let a = 4;
let b = 2;
function (){
  return a + b + 100;
}

// Arrow Function (no arguments)
let a = 4;
let b = 2;
() => a + b + 100;

arrow function

const doSomething = () => {
  // Function Scope
};

An Arrow Function

/*The arrow functions were introduced in ECMA 2015 with the main purpose of giving a shorter syntax to a function expression. 
Besides providing shorter syntax, which increases the readability of the code, 
it does not have its own value of the this object. The value of this object inside an arrow function is inherited from the enclosing scope.

You can write an arrow function to add two numbers as shown in the next code example.*/

var add = (num1, num2)=> num1+num2; 
let res = add(5,2);
console.log(res); // 7 

es6 arrow function

//ES5
var phraseSplitterEs5 = function phraseSplitter(phrase) {
  return phrase.split(' ');
};

//ES6
const phraseSplitterEs6 = phrase => phrase.split(" ");

console.log(phraseSplitterEs6("ES6 Awesomeness"));  // ["ES6", "Awesomeness"]

es6 arrow function

const multiplyES6 = (x, y) => x * y;

Javascript basic arrow function

const power = (base, exponent) => {
    let result = 1;
    for (let count = 0; count < exponent; count++) {
      result *= base;
    }
    return result;
  };

arrow functions javascript

// Traditional Function Expression
var add = function(a,b){
  return a + b;
}

// Arrow Function Expression
var arrowAdd = (a,b) => a + b;

arrow function

const = newfunc =(a,b)=>{
	return a+b
}

shorthand arrow function

const = newfunc = (a,b)=> a+b

Arrow function in ES6

var array = [1, 2, 3, 4]

const sum = (acc, value) => acc + value
const product = (acc, value) => acc * value

var sumOfArrayElements = array.reduce(sum, 0)
var productOfArrayElements = array.reduce(product, 1)

arrow function javascript rules

const add3 = (num1, num2, num3) => return num1 + num2 + num3;

Arrow Function Example

let nums = [3, 5, 7]
let squares = nums.map(function (n) {
  return n * n
})
console.log(squares)

arrow function

const hello = () => {  
 return 'Hello'
}

const hello = () => 'Hello'
console.log(hello())

arrow functions

let add = (x, y) => x + y;

console.log(add(10, 20)); // 30;
Code language: JavaScript (javascript)

arrow functions=>

(param1, paramN) => {
   let a = 1;
   return a + param1 + paramN;
}

arrow function

const bk = () =>{
   console.log("Bk function called");
}
bk()

arrow function javascript rules

const square = num => num ** 2;

arrow function javascript rules

const sayHi = ()=>console.log('Hi');

Learning Arrow function Syntax

// Traditional Function
function bob (a){
  return a + 100;
}
// 1. Remove the word "function" and place arrow between the argument and opening body bracket
// Arrow Function
// 2. Remove the body braces and word "return" -- the return is implied
// 3. Remove the argument parentheses

// Arrow Function
let bob = a => a + 100;

es6 arrow function

// ES6
const prices = smartPhones.map(smartPhone => smartPhone.price);
console.log(prices); // [649, 576, 489]

arrow functions=>

// Traditional Anonymous Function
function (a, b){
  let chuck = 42;
  return a + b + chuck;
}

// Arrow Function
(a, b) => {
  let chuck = 42;
  return a + b + chuck;
}

arrow function

textBox.addEventListener('keydown', (event) => {
  console.log(`You pressed "${event.key}".`);
});

javascript Arrow Function Syntax

let myFunction = (arg1, arg2, ...argN) => {
    statement(s)
}

Arrow functions javascript

// Arrow function with two arguments 
const sum = (firstParam, secondParam) => { 
  return firstParam + secondParam; 
}; 
console.log(sum(2,5)); // Prints: 7 
 
// Arrow function with no arguments 
const printHello = () => { 
  console.log('hello'); 
}; 
printHello(); // Prints: hello
 
// Arrow functions with a single argument 
const checkWeight = weight => { 
  console.log(`Baggage weight : ${weight} kilograms.`); 
}; 
checkWeight(25); // Prints: Baggage weight : 25 kilograms.
 
 
// Concise arrow functions
const multiply = (a, b) => a * b; 
console.log(multiply(2, 30)); // Prints: 60

Arrow Function Example

let nums = [3, 5, 7]
let squares = nums.map((n) => {
  return n * n
})
console.log(squares)

ES6 arrow functions in JavaScript

const greeting = () => console.log('Hello World'); 

arrow function

// Traditional Function
function (a){
  return a + 100;
}

// Arrow Function Break Down

// 1. Remove the word "function" and place arrow between the argument and opening body bracket
(a) => {
  return a + 100;
}

// 2. Remove the body brackets and word "return" -- the return is implied.
(a) => a + 100;

// 3. Remove the argument parentheses
a => a + 100;

arrow functions javascript

const myFunc = () => "value";

arrow function

// Arrow function with two arguments const sum = (firstParam, secondParam) => {   return firstParam + secondParam; }; console.log(sum(2,5)); // Prints: 7  // Arrow function with no arguments const printHello = () => {   console.log('hello'); }; printHello(); // Prints: hello // Arrow functions with a single argument const checkWeight = weight => {   console.log(`Baggage weight : ${weight} kilograms.`); }; checkWeight(25); // Prints: Baggage weight : 25 kilograms.  // Concise arrow functionsconst multiply = (a, b) => a * b; console.log(multiply(2, 30)); // Prints: 60 

arrow function Java Script

param => expression
(param) => expression

// Arrow Function
(a, b) => {
  const chuck = 42;
  return a + b + chuck;
};

Arrow functions syntax

const introduction = () => {
    console.log("Hello, my name is Jessica.");
};