JS Functions

function declaration

    

function myFunction() {

}

myFunction();

return keyword

    

function myFunction() {
  let a = 'hello world';
  return a;
}

let b = myFunction();

function with one parameter

    

function myFunction(param1) {

}

myFunction(arg1);

function with two parameters

    

function myFunction(param1, param2) {

}

myFunction(arg1, arg2);

function expression

    

let myFunction = function() {

}

Arrow function (no parameters)

    

// No arguments
() => {
  return 'hello world';
}

() => 'hello world';

Arrow function (one parameter)

    

// 1 argument
(a) => {
return a + 1;
}

// No curly braces
(a) => a + 1;

// No parentheses
a => a + 1;

Arrow function (multiple parameters)

    

// 2+ arguments
(a, b) => {
return a + b;
}

// No curly braces
(a, b) => a + b;