[프로그래머스]Lv.1 핸드폰 번호 가리기 C#(padLeft)

https://school.programmers.co.kr/learn/courses/30/lessons/12948

프로그래머스

소스코드1

public class Solution
{
    public string solution(string phone_number)
    {
        string answer = "";

        char[] array = phone_number.ToCharArray();
        for (int i = 0; i < phone_number.Length - 4; i++)
        {
            array[i] = '*';
        }
        return new string(array);
    }
}

소스코드2

public class Solution
{
    public string solution(string phone_number)
    {
        string answer = phone_number.Substring(phone_number.Length - 4);
        answer = answer.PadLeft(phone_number.Length, '*');

        return answer;
    }
}