arrow function syntax js 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: javascript arrow function

// Non Arrow (standard way)
let add = function(x,y) {
  return x + y;
}
console.log(add(10,20)); // 30

// Arrow style
let add = (x,y) => x + y;
console.log(add(10,20)); // 30;

// You can still encapsulate
let add = (x, y) => { return x + y; };

Example 3: 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 4: javascript arrow function

const welcome = () => {
	console.log("THIS IS A ARROW FUNCTION")
}

Example 5: javascript this inside arrow function

function A() {
  this.val = "Error";
  (function() {
    this.val = "Success";
  })();
}

function B() {
  this.val = "Error";
  (() => {
    this.val = "Success";
  })();
}

var a = new A();
var b = new B();
a.val // "Error"
b.val // "Success"

Example 6: concise body arrow functions javascript

const plantNeedsWater = day => day === 'Wednesday' ? true : false;

//If only 1 Parameter no () needed
//Single line return is implicit
//Single line no {} needed