04 array.map()

let numbers = [1,2,3,4,5];
let newNumbers = numbers.map(n=>n*2);
console.log(newNumbers);
//2,4,6,8,10

map 메서드로 출력하기 

arr.map(callback(currentValue[, index[, array]])[, thisArg])

developer.mozilla.org/ko/docs/Web/JavaScript/Reference/Global_Objects/Array/map