[Java] 진법 변환 정리

10진수 -> n진수

• 10진수를 제외한 나머지 진수는 String으로 받음
• 2진수 toBinaryString(num)
• 8진수 toOctalString(num)
• 16진수 toHexString(num)

public class Solution {
    public static void main(String[] args) {
        int a = 25;

        System.out.println("10진수 -> 2진수");
        System.out.println(Integer.toBinaryString(a));
        System.out.println(Integer.toString(a,2));

        System.out.println("10진수 -> 3진수");
        System.out.println(Integer.toString(a,3));

        System.out.println("10진수 -> 4진수");
        System.out.println(Integer.toString(a,4));

        System.out.println("10진수 -> 5진수");
        System.out.println(Integer.toString(a,5));

        System.out.println("10진수 -> 6진수");
        System.out.println(Integer.toString(a,6));

        System.out.println("10진수 -> 7진수");
        System.out.println(Integer.toString(a,7));

        System.out.println("10진수 -> 8진수");
        System.out.println(Integer.toOctalString(a));
        System.out.println(Integer.toString(a,8));

        System.out.println("10진수 -> 16진수");
        System.out.println(Integer.toString(a,16));
        System.out.println(Integer.toHexString(a));
    }
}

 

 

n진수 -> 10진수

• Integer.parseInt(string s, int radix) radix에 해당 값이 몇 진수인지 넣어주어야 함

public class Solution {
    public static void main(String[] args) {

        String a = "110011";

        System.out.println("2진수 -> 10진수");
        System.out.println(Integer.parseInt(a,2));

        System.out.println("3진수 -> 10진수");
        System.out.println(Integer.parseInt(a,3));

        System.out.println("4진수 -> 10진수");
        System.out.println(Integer.parseInt(a,4));

        System.out.println("5진수 -> 10진수");
        System.out.println(Integer.parseInt(a,5));

        System.out.println("6진수 -> 10진수");
        System.out.println(Integer.parseInt(a,6));

        System.out.println("7진수 -> 10진수");
        System.out.println(Integer.parseInt(a,7));

        System.out.println("8진수 -> 10진수");
        System.out.println(Integer.parseInt(a,8));

        System.out.println("16진수 -> 10진수");;
        System.out.println(Integer.parseInt(a,16));
    }
}