arrow function javascript

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 optionconst suma = (num1, num2) => num1+num2
console.log(suma(2,3));
//5hello = () => {
  return "Hello World!";
}// an arrow function is also called a lambda or an anonymous function

let myFunction = () => {
  // some logic
}/* Answer to: "arrow function javascript" */

// Single-line:
let testingFunc(string) => string == "Test" ? "Success!" : "Failure!";
console.log(testingFunc("test")); // "Failure!"

// Multi-line:
let arrowFunc(string) => {
  if (string = "test") {
    return "Success!";
  }
    return "Failure!";
  }
};
console.log(testingFunc("Test")); // "Success!"

/*
  Arrow functions in JavaScript are like regular functions except they look
  look nicer (imo) and there's single-line version of it which implicitly
  returns.
  
  Here's a guide showing the differences between the two:
  https://medium.com/better-programming/difference-between-regular-functions-and-arrow-functions-f65639aba256
  > The link will also be in the source below.
*/const power = (base, exponent) => {
  let result = 1;
  for (let count = 0; count < exponent; count++) {
    result *= base;
  }
  return result;
};

//if the function got only one parameter

const square1 = (x) => { return x * x; };
const square2 = x => x * x;

// empty parameter

const horn = () => {
  console.log("Toot");
};// An empty arrow function returns undefined
let empty = () => {};

(() => 'foobar')();
// Returns "foobar"
// (this is an Immediately Invoked Function Expression)

var simple = a => a > 15 ? 15 : a;
simple(16); // 15
simple(10); // 10

let max = (a, b) => a > b ? a : b;

// Easy array filtering, mapping, ...

var arr = [5, 6, 13, 0, 1, 18, 23];

var sum = arr.reduce((a, b) => a + b);
// 66

var even = arr.filter(v => v % 2 == 0);
// [6, 0, 18]

var double = arr.map(v => v * 2);
// [10, 12, 26, 0, 2, 36, 46]

// More concise promise chains
promise.then(a => {
  // ...
}).then(b => {
  // ...
});

// Parameterless arrow functions that are visually easier to parse
setTimeout( () => {
  console.log('I happen sooner');
  setTimeout( () => {
    // deeper code
    console.log('I happen later');
  }, 1);
}, 1);
// Traditional Function
function (a, b){
  return a + b + 100;
}

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

// Traditional 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;params => ({foo: "a"}) // returning the object {foo: "a"}// Traditional Function
function bob (a){
  return a + 100;
}

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

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