Map() 함수 생성
Map() Udpate
값 검색(get() method 활용)
[for ...of 반복문]
The Javascript map() method creates an array by calling a specific function on each element present in the parent array. It is a non-mutating method. Generally, the map() method is used to iterate over an array and call function on every element of the array.
This method accepts two parameters.
It returns a new array and elements of arrays are the result of the callback function.