import java.util.Scanner;

public class H_to_B {

    static void HtoB_fun(String n){

        char[] ch=n.toCharArray();

        char str;

        String s="";

        int p=0;

        for(int i=0;i            str=ch[i];

            if(str>='0'&&str<='9'){

                String st= Character.toString(str);//字符转字符串

                p=Integer.valueOf(st).intValue();//字符串转整型

            }

            else{

                if(str=='A'){str=10;}

                if(str=='B'){str=11;}

                if(str=='C'){str=12;}

                if(str=='D'){str=13;}

                if(str=='E'){str=14;}

                if(str=='F'){str=15;}

                if(str=='.'){str=16;}

                p=(int)str;

            }

            switch (p){

            case 0 : 

                s+="0000";

                break;

            case 1 : 

                s+="0001";

                break;

            case 2 : 

                s+="0010";

                break;

            case 3 : 

                s+="0011";

                break;

            case 4 : 

                s+="0100";

                break;

            case 5 : 

                s+="0101";

                break;

            case 6 : 

                s+="0110";

                break;

            case 7 : 

                s+="0111";

                break;

            case 8 : 

                s+="1000";

                break;

            case 9 : 

                s+="1001";

                break;

            case 10 : 

                s+="1010";

                break;

            case 11 : 

                s+="1011";

                break;

            case 12 : 

                s+="1100";

                break;

            case 13 : 

                s+="1101";

                break;

            case 14 : 

                s+="1110";

                break;

            case 15 : 

                s+="1111";

                break;

            case 16 : 

                s+=".";

                break;

            default :

                System.out.println("error!");

                break;

            }

        }

        System.out.println("结果为二进制：");

        System.out.println(s);

    }

    public static void main(String[] args) {

        Scanner sc=new Scanner(System.in);

        System.out.println("请输入16进制数：");

        String str=sc.nextLine();

        HtoB_fun(str);

    }

}

//二进制数转十六进制数

import java.util.Scanner;

public class B_to_H {

    static void BtoH_fun(String str){

        String s=""; //s 用来接收每位十六进制数的位数

        int chushihua=0;//判断是否有小数点

        int west=0,wei=0;//小数点的位置

        int c;

        char[] ch1=str.toCharArray();

        for(int i=0;i            if(ch1[i]=='.'){

                chushihua=1;

                west=i;

            }

        }

        if(chushihua==1){

            int jud=4-(west%4);

            int jud1=4-((str.length()-1-west)%4);

            if(jud!=0&&jud!=4){

                for(int i=0;i            }

            if(jud1!=0&&jud1!=4){

                for(int i=0;i            }

            wei=str.indexOf(".")+1;

            str=str.replace(".", "");

        }

        if(chushihua==0){

            int judge=4-(str.length()%4);//前面该补judge个0

            if(judge!=0&&judge!=4){    //当str.length()%4为0时，judge为4，所以要加judge!=4这个条件

                for(int i=1;i<=judge;i++){

                    str="0"+str;

                }

            }

        }    

        char[] ch=str.toCharArray();

        int[] a=new int[str.length()];

        for(int i=0;i            String st=Character.toString(ch[i]);//把字符转换为字符串

            a[i]=Integer.valueOf(st).intValue(); //再把字符串转换为整型

            //System.out.print(a[i]);  //用来测试是否在前面补零

        }

            for(int i=1;i<=str.length();i++){

                if(i==wei&&wei!=0){s+=".";}

                if(i%4==0){

                    c=a[i-1]*1+a[i-2]*2+a[i-3]*4+a[i-4]*8;

                    if(c<10){

                        int b=a[i-1]*1+a[i-2]*2+a[i-3]*4+a[i-4]*8;

                        s+=b+"";

                    }

                    if(c>=10){

                        switch(c){

                            case 10 :

                                s+="A";

                                break;

                            case 11 :

                                s+="B";

                                break;

                            case 12 :

                                s+="C";

                                break;

                            case 13 :

                                s+="D";

                                break;

                            case 14 :

                                s+="E";

                                break;

                            case 15 :

                                s+="F";

                                break;

                        }

                    }

                }

        }

        System.out.println("结果为十六进制数："+s);

    }

    public static void main(String[] args) {

        long startTime = System.currentTimeMillis(); 

        Scanner sc=new Scanner(System.in);

        System.out.println("请输入一串二进制数字：");

        String str=sc.nextLine();

        //String str="101001011011111101010001";

        BtoH_fun(str);

        long endTime = System.currentTimeMillis(); 

        long usedTime = endTime - startTime;

        System.out.println("程序执行所用时间："+usedTime+" 毫秒！");

    }

}下载本文