functions.js

function myFunction (age, name) {
  arguments[0]
  console.log(`my name is ${name} and my age ${age}`)
}

`
"function" is the keyword that tells JS that we are about
to define a function

"(stuff1, stuff2...)" contain parameters which say
what local variable will be called in the function block
when they are passed in as arguments when the function is run/called/invoked. ORDER MATTERS!

"{ ... }" function block, defines what the function does

ALL functions return something. if you don't use the "return" keyword to return a value, it automatically returns "undefined"
`

myFunction(25, 'Bethany')
"my name is Bethany and my age is 25"

/*
default arguments can be used to tell a function what values
to use if arguments are not provided
*/
function addTwoNumbers (num1 = 1, num2 = 3) {
  return num1 + num2
}

addTwoNumbers(4,5)
// 9

addTwoNumbers()
// 4

addTwoNumbers(10)
// 13








/* 
different function definition syntaxes
*/

// function declaration syntax
function otherFunction () {
  console.log('hi')
}

// function assignment syntax
const otherFunction = function () {
  console.log('hi')
}

// ES6 syntax - arrow functions
const otherFunction = () => {
  console.log('hi')
}

// single line block can remove {} and put on
// same line as function name - all on one line
const otherFunction = () => console.log('hi')

// additionally, if that single line in the block
// was to return a value, you can remove the return
// keyword as well and it will still return! this
// is called "implicit return"
const otherFunction2 = () => {
  return 'hello'
}

const otherFunction2 = () => 'hello'

// when your function has a single param, you
// can remove the parentheses
const thisFunction = (name) => console.log(name)

const thisFunction = name => console.log(name)

// that won't work with more than one param
const thisFunction = (name, age) => console.log(name, age)