: μ‘°κΈ λ μ°κ΄μλ λ°μ΄ν°λ₯Ό νλ° λ¬Άμ΄ λλ 컨ν μ΄λ!!
class : μ²μ¬μ§ template declare once no data in
class : μ²μ¬μ§
object instance of a class created many times data in
object