Java 16进制转10进制

牛课网上的题目

char '1'和 int 1给我好好上了一课

package suanfa;

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        while(in.hasNext()){        
            String s = in.nextLine();
            s = s.substring(2);
            int l = s.length();
            char[] ch = s.toCharArray();
            int sum = 0;
            int j = 1;
            int temp = 0;
            for(int i = l-1; i >= 0; i--){
                if(ch[i] == 'A'){
                    temp = 10;
                }
                else if(ch[i] == 'B'){
                    temp = 11;
                }
                else if(ch[i] == 'C'){
                    temp = 12;
                }
                else if(ch[i] == 'D'){
                    temp = 13;
                }
                else if(ch[i] == 'E'){
                    temp = 14;
                }
                else if(ch[i] == 'F'){
                    temp = 15;
                }
                else{
                    temp = (int)ch[i] - (int)'0';
                    //一开始直接 temp = ch[i]得到的是ASCII码
                }
                //System.out.println(ch[i]);
                //System.out.println(sum);
                //System.out.println(j);
                //System.out.println(temp);
                sum=sum + j*temp;
                
                j = j*16;
                
            }
            System.out.println(sum);
            
        }
    }
}