js arrow function this code example

Example 1: arrow function rec

(param1, param2, …, paramN) => { statements } 
(param1, param2, …, paramN) => expression
// equivalent to: => { return expression; }

// Parentheses are optional when there's only one parameter name:
(singleParam) => { statements }
singleParam => { statements }

// The parameter list for a function with no parameters should be written with a pair of parentheses.
() => { statements }

Example 2: js arrow function

// const add = function(x,y) {
//     return x + y;
// }

// const add = (x, y) => {
//     return x + y;
// }

const add = (a, b) => a + b;


const square = num => {
    return num * num;
}

// const rollDie = () => {
//     return Math.floor(Math.random() * 6) + 1
// }

const rollDie = () => (
    Math.floor(Math.random() * 6) + 1
)

Example 3: js arrow function this

const person = {
    firstName: 'Viggo',
    lastName: 'Mortensen',
    fullName: function () {
        return `${this.firstName} ${this.lastName}`
    },
    shoutName: function () {
        setTimeout(() => {
            //keyword 'this' in arrow functions refers to the value of 'this' when the function is created
            console.log(this);
            console.log(this.fullName())
        }, 3000)
    }
}

Example 4: arrow function in javascript

//function old way
function PrintName(name){
  console.log("my name is ", name) ;
}
// Arrow function es6
const PrintName =  (name) => {
  return console.log("my name is " , name) ;
}

Example 5: arrow function javascript

//If body has single statement
let myFunction = (arg1, arg2, ...argN) => expression

//for multiple statement
let myFunction = (arg1, arg2, ...argN) => {
    statement(s)
}
//example
let hello = (arg1,arg2) => "Hello " + arg1 + " Welcome To "+ arg2;
console.log(hello("User","Grepper"))
//Start checking js code on chrome inspect option

Example 6: arrow func in javascript

const greet = (who) => {
  return `Hello, ${who}!`;
};

greet('Eric Cartman'); // => 'Hello, Eric Cartman!'