JAVASCRIPT

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 

arrow function

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

shorthand arrow function

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

arrow function

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

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

arrow functions=>

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

arrow function

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

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 Shorthand javascript

// Arrow Functions Shorthand javascript
// Longhand:
function sayHello(name) {
  console.log('Hello', name);
}
sayHello("Chetan"); // Hello Chetan

setTimeout(function() {
  console.log('Loaded'); //Loaded
}, 2000);

[1,2,3].forEach(function(item) {
  console.log(item);
// 1
// 2
// 3
});

// Shorthand:
sayHello = name => console.log('Hello', name);
sayHello("Chetan"); //Hello Chetan

setTimeout(() => console.log('Loaded'), 2000); //Loaded

[1,2,3].forEach(item => console.log(item));
// 1
// 2
// 3

arrow function

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

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 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 functions syntax

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