closures.js

/**
* go to the exercises => http://csbin.io/closures
*
*/

// CHALLENGE 1
function createFunction() {
	function sayHello() {
    console.log('hello');
  }
  
  return sayHello;
}

// /*** Uncomment these to check your work! ***/
const function1 = createFunction();
function1(); // => should console.log('hello');


// CHALLENGE 2
function createFunctionPrinter(input) {
	function sayTheInput() {
    console.log(input);
  }
  
  return sayTheInput;
}

// /*** Uncomment these to check your work! ***/
const printSample = createFunctionPrinter('sample');
printSample(); // => should console.log('sample');
const printHello = createFunctionPrinter('hello');
printHello(); // => should console.log('hello');


// CHALLENGE 3
function outer() {
  let counter = 0; // this variable is outside incrementCounter's scope
  function incrementCounter () {
    counter ++;
    console.log('counter', counter);
  }
  return incrementCounter;
}

const willCounter = outer();
const jasCounter = outer();

// Uncomment each of these lines one by one.
// Before your do, guess what will be logged from each function call.

// /*** Uncomment these to check your work! ***/
willCounter();
willCounter();
willCounter();

jasCounter();
willCounter();


function addByX(x) {
  function incrementCounter(y) {
    console.log('addByX', x + y);
    return x + y;
  }
  return incrementCounter;
}

// /*** Uncomment these to check your work! ***/
const addByTwo = addByX(2);
addByTwo(1); // => should return 3
addByTwo(2); // => should return 4
addByTwo(3); // => should return 5

const addByThree = addByX(3);
addByThree(1); // => should return 4
addByThree(2); // => should return 5

const addByFour = addByX(4);
addByFour(4); // => should return 8
addByFour(5); // => should return 9


// CHALLENGE 4
function once(func) {
  let output;
	function execCallback(number) {
    if (!output) {
      output = func(number);
    }
    
    return output;
  }
  
  return execCallback
}

// /*** Uncomment these to check your work! ***/
console.log('############## onceFn')
const onceFunc = once(addByTwo);
console.log(onceFunc(4));  // => should log 6
console.log(onceFunc(10));  // => should log 6
console.log(onceFunc(9001));  // => should log 6


// CHALLENGE 5
function after(count, func) {

}

// /*** Uncomment these to check your work! ***/
// const called = function() { console.log('hello') };
// const afterCalled = after(3, called);
// afterCalled(); // => nothing is printed
// afterCalled(); // => nothing is printed
// afterCalled(); // => 'hello' is printed


// CHALLENGE 6
function delay(func, wait) {

}


// CHALLENGE 7
function rollCall(names) {

}

// /*** Uncomment these to check your work! ***/
// const rollCaller = rollCall(['Victoria', 'Juan', 'Ruth'])
// rollCaller() // => should log 'Victoria'
// rollCaller() // => should log 'Juan'
// rollCaller() // => should log 'Ruth'
// rollCaller() // => should log 'Everyone accounted for'


// CHALLENGE 8
function saveOutput(func, magicWord) {

}

// /*** Uncomment these to check your work! ***/
// const multiplyBy2 = function(num) { return num * 2; };
// const multBy2AndLog = saveOutput(multiplyBy2, 'boo');
// console.log(multBy2AndLog(2)); // => should log 4
// console.log(multBy2AndLog(9)); // => should log 18
// console.log(multBy2AndLog('boo')); // => should log { 2: 4, 9: 18 }


// CHALLENGE 9
function cycleIterator(array) {

}

// /*** Uncomment these to check your work! ***/
// const threeDayWeekend = ['Fri', 'Sat', 'Sun'];
// const getDay = cycleIterator(threeDayWeekend);
// console.log(getDay()); // => should log 'Fri'
// console.log(getDay()); // => should log 'Sat'
// console.log(getDay()); // => should log 'Sun'
// console.log(getDay()); // => should log 'Fri'


// CHALLENGE 10
function defineFirstArg(func, arg) {

}

// /*** Uncomment these to check your work! ***/
// const subtract = function(big, small) { return big - small; };
// const subFrom20 = defineFirstArg(subtract, 20);
// console.log(subFrom20(5)); // => should log 15


// CHALLENGE 11
function dateStamp(func) {

}

// /*** Uncomment these to check your work! ***/
// const stampedMultBy2 = dateStamp(n => n * 2);
// console.log(stampedMultBy2(4)); // => should log { date: (today's date), output: 8 }
// console.log(stampedMultBy2(6)); // => should log { date: (today's date), output: 12 }


// CHALLENGE 12
function censor() {

}

// /*** Uncomment these to check your work! ***/
// const changeScene = censor();
// changeScene('dogs', 'cats');
// changeScene('quick', 'slow');
// console.log(changeScene('The quick, brown fox jumps over the lazy dogs.')); // => should log 'The slow, brown fox jumps over the lazy cats.'


// CHALLENGE 13
function createSecretHolder(secret) {

}

// /*** Uncomment these to check your work! ***/
// obj = createSecretHolder(5)
// obj.getSecret() // => returns 5
// obj.setSecret(2)
// obj.getSecret() // => returns 2


// CHALLENGE 14
function callTimes() {

}

// /*** Uncomment these to check your work! ***/
// let myNewFunc1 = callTimes();
// let myNewFunc2 = callTimes();
// myNewFunc1(); // => 1
// myNewFunc1(); // => 2
// myNewFunc2(); // => 1
// myNewFunc2(); // => 2


// CHALLENGE 15
function russianRoulette(num) {

}

// /*** Uncomment these to check your work! ***/
// const play = russianRoulette(3);
// console.log(play()); // => should log 'click'
// console.log(play()); // => should log 'click'
// console.log(play()); // => should log 'bang'
// console.log(play()); // => should log 'reload to play again'
// console.log(play()); // => should log 'reload to play again'


// CHALLENGE 16
function average() {

}

// /*** Uncomment these to check your work! ***/
// const avgSoFar = average();
// console.log(avgSoFar()); // => should log 0
// console.log(avgSoFar(4)); // => should log 4
// console.log(avgSoFar(8)); // => should log 6
// console.log(avgSoFar()); // => should log 6
// console.log(avgSoFar(12)); // => should log 8
// console.log(avgSoFar()); // => should log 8


// CHALLENGE 17
function makeFuncTester(arrOfTests) {
  
}

// /*** Uncomment these to check your work! ***/
// const capLastTestCases = [];
// capLastTestCases.push(['hello', 'hellO']);
// capLastTestCases.push(['goodbye', 'goodbyE']);
// capLastTestCases.push(['howdy', 'howdY']);
// const shouldCapitalizeLast = makeFuncTester(capLastTestCases);
// const capLastAttempt1 = str => str.toUpperCase();
// const capLastAttempt2 = str => str.slice(0, -1) + str.slice(-1).toUpperCase();
// console.log(shouldCapitalizeLast(capLastAttempt1)); // => should log false
// console.log(shouldCapitalizeLast(capLastAttempt2)); // => should log true


// CHALLENGE 18
function makeHistory(limit) {

}

// /*** Uncomment these to check your work! ***/
// const myActions = makeHistory(2);
// console.log(myActions('jump')); // => should log 'jump done'
// console.log(myActions('undo')); // => should log 'jump undone'
// console.log(myActions('walk')); // => should log 'walk done'
// console.log(myActions('code')); // => should log 'code done'
// console.log(myActions('pose')); // => should log 'pose done'
// console.log(myActions('undo')); // => should log 'pose undone'
// console.log(myActions('undo')); // => should log 'code undone'
// console.log(myActions('undo')); // => should log 'nothing to undo'


// CHALLENGE 19
function blackjack(array) {

}

// /*** Uncomment these to check your work! ***/

// /*** DEALER ***/
// const deal = blackjack([2, 6, 1, 7, 11, 4, 6, 3, 9, 8, 9, 3, 10, 4, 5, 3, 7, 4, 9, 6, 10, 11]);

// /*** PLAYER 1 ***/
// const i_like_to_live_dangerously = deal(4, 5);
// console.log(i_like_to_live_dangerously()); // => should log 9
// console.log(i_like_to_live_dangerously()); // => should log 11
// console.log(i_like_to_live_dangerously()); // => should log 17
// console.log(i_like_to_live_dangerously()); // => should log 18
// console.log(i_like_to_live_dangerously()); // => should log 'bust'
// console.log(i_like_to_live_dangerously()); // => should log 'you are done!'
// console.log(i_like_to_live_dangerously()); // => should log 'you are done!'

// /*** BELOW LINES ARE FOR THE BONUS ***/

// /*** PLAYER 2 ***/
// const i_TOO_like_to_live_dangerously = deal(2, 2);
// console.log(i_TOO_like_to_live_dangerously()); // => should log 4
// console.log(i_TOO_like_to_live_dangerously()); // => should log 15
// console.log(i_TOO_like_to_live_dangerously()); // => should log 19
// console.log(i_TOO_like_to_live_dangerously()); // => should log 'bust'
// console.log(i_TOO_like_to_live_dangerously()); // => should log 'you are done!
// console.log(i_TOO_like_to_live_dangerously()); // => should log 'you are done!

// /*** PLAYER 3 ***/
// const i_ALSO_like_to_live_dangerously = deal(3, 7);
// console.log(i_ALSO_like_to_live_dangerously()); // => should log 10
// console.log(i_ALSO_like_to_live_dangerously()); // => should log 13
// console.log(i_ALSO_like_to_live_dangerously()); // => should log 'bust'
// console.log(i_ALSO_like_to_live_dangerously()); // => should log 'you are done!
// console.log(i_ALSO_like_to_live_dangerously()); // => should log 'you are done!