// 예제 4-5
Array.prototype.map2 = function(callback, thisArg) {
  var mappedArr = [];
  for (var i = 0; i < this.length; i++) {
    var mappedValue = callback.call(thisArg || window, this[i], i, this);
    mappedArr[i] = mapppedValue;
  }
  return mappedArr;
}

Array.prototype.filter2 = function(callback, thisArg) {
  var filteredArr = [];
  for (var i = 0; i < this.length; i++) {
    var isTrue = callback.call(thisArg || window, this[i], i, this);
    if (isTrue) {
      filteredArr.push(this[i]);
    }
  }
  return filteredArr;
}

var addCoffee = function(name) {
  return function(prevName) {
    return new Promise(function(resolve) {
      setTimeout(function() {
        var newName = prevName ? (prevName + ', ' + name) : name;
        console.log(newName);
        resolve(newName);
      }, 500);
    });
  };
};
// 이 아래 코드들
addCoffee('에스프레소')()
.then(addCoffee('아메리카노'))
.then(addCoffee('카페모카'))
.then(addCoffee('카페라떼'))

addCoffee('에스프레소')()
.then(prevName => addCoffee('아메리카노')(prevName))
.then(prevName => addCoffee('카페모카')(prevName))
.then(prevName => addCoffee('카페라떼')(prevName))

// 비슷한 예시
[1, 2, 3, 4, 5].forEach(console.log) 

async function getDelay(target, second) {
	return new Promise((resolve, reject) => {
		setTimeout(() => resolve(target), second * 1000);
    })
	}

console.log(await getDelay('비동기', 5)); // 5초 뒤에 '비동기' 출력