C#

System.Console // static?

.WriteLine() // static

.Write() // static
.ReadLine() // static
.Read() // static

    static int ReadInt()
    {
        char ch;
        int n = 0;

        while (!char.IsDigit(ch = (char)Console.Read())) ;

        do
        {
            n = n * 10 + (ch - '0');
            ch = (char)Console.Read();
        } while (char.IsDigit(ch));

        return n;
    }

System.IFormattable

string ToString(string format, IFormatProvider formatProvider);

using System;

class Time : IFormattable

{

public int hour, min, sec;

public Time(int h, int m, int s) { hour = h; min = m; sec = s; }

public String ToString(string format, IFormatProvider fp) {

switch (format) {

case null:

case "A":

return string.Format("{0}시 {1}분 {2}초", hour, min, sec);

case "B":

return string.Format("{0}:{1}:{2}", hour, min, sec);

case "C":

return string.Format("{0}.{1}.{2}", hour, min, sec);

default:

return "틀린 서식입니다.";

}

}

}

class CSTest

{

static void Main() {

Time Now = new Time(12, 34, 56);

Console.WriteLine("Now = {0:A}입니다.", Now);

Console.WriteLine("Now = {0:B}입니다.", Now);

Console.WriteLine("Now = {0:C}입니다.", Now);

Console.WriteLine("Now = {0,20}입니다.", Now);

Console.WriteLine("Now = {0,-20}입니다.", Now);

}

}