[Java] Implicit type cast (AOJ10-sum of numbers)

Type cast

• ** char type can be implicitly cast to int type or double type **
• Char type wrapper class Character type is Unicode character representation
• For "1" U + 0031 (hexadecimal) 49 (decimal)
• If char type "1" is implicitly cast to int type, "49" is output.
• I was allowed to reference
  • Why we use -'0' beside charAt(i)?
• [Java] char type can be cast to int type @ nkojima article

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

        char c = '1';
        //Implicitly cast to int type, double type
        int i = c;
        double d = c;
        System.out.println(c + "To int type →" + i);
        System.out.println(c + "To double type →" + d);

        //Pass char type as an argument to a method whose argument is double type
        doubleMethod(c);
    }

    static void doubleMethod(double d) {
        System.out.println("double type →" + d);
    }
}

Cast 1 to int type → 49
Cast 1 to double type → 49.0
double type → 49.0

Sum of numbers (ITP1-8)

Create a program that calculates the sum of each digit of a given number. Input Multiple datasets are given as input. Each dataset is given in one line containing one integer x. x is an integer of 1000 digits or less. When x is 0, the input ends. Do not output to this dataset. Output For each data set, output the sum of each digit of x on one line.

• Implicitly casting with ans + = line.charAt (i)-‘0’; in this example
• line.charAt (i) returns char
• ans is an integer, so convert it to an integer

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int ans;

        while(true){
    	String line = br.readLine();
    	    if(line.length() == 1 && line.equals("0")){
    	        break;
    	    }else{
        	    ans= 0;
        	    for(int i = 0; i < line.length(); i++){
        		    ans += line.charAt(i)-'0';
        	    
        	   /*Confirmation of type cast
        	   System.out.println("line.charAt(i) "+line.charAt(i));
    	       System.out.println("line[i] "+(int)line.charAt(i));
               System.out.println("(int)'0' "+(int)'0');
               */
    	       }
    	       System.out.println(ans);

    	    }
        }
    }
}