闲来无事,写了一个求二进制的类:
import java.util.Scanner; public class ErJinZhi { public static void main(String[] args) { boolean want = true; while (want) { System.out.print("请输入一个整数:"); Scanner scanner = new Scanner(System.in); int index; try { index = scanner.nextInt(); } catch (Exception e) { System.out.println("输入错误!!!"); want = true; continue; } System.out.println(index + " 的二进制是 " + erJinZhi(index)); System.out.print("你想继续吗?(y/n):"); do { String c = scanner.next(); if (c.equals("n") || c.equals("N")) { want = false; System.out.println("exit !!!"); break; } else if (c.equals("y") || c.equals("Y")) { want = true; break; } else { System.out.print("\n请继续选择(y/n):"); continue; } } while (true); } } private static String erJinZhi(int index) { String erjizhi = ""; while (true) { if (index >= 2) { int yu = index % 2; index = index / 2; erjizhi = yu + erjizhi; continue; } else { erjizhi = index + erjizhi; break; } } return erjizhi; } }