Question

Design a program that will receive a valid time in the 12-hour format (e.g. 11:05 PM) and convert it to its equivalent 24-hour format (e.g. 2305). Assume 0000 in 24-hour format is 12:00AM in 12-hour format. The program should continue accepting inputs until a sentinel value of 99:99AM is entered.

Ex: If the input is:

09:04AM 10:45AM 11:23AM 99:99AM

IN Java please, Thanks

the output is:

0904 1045 1123

Answer 1

/*

I wrote as simple as I can reach me out if u need any changes

*/

//Convert 12-hour time to 24-hour time format

import java.io.*;
public class Main
{
   public static void main(String[] args) throws IOException {
       BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
       String str=br.readLine();
       while(!str.equals("99:99AM")){
       System.out.println(getConvertedTime(str));
       str=br.readLine();
       }
   }
   public static String getConvertedTime(String str){
   String s=str.substring(str.length()-2);
   String[] hoursAndMinutes=str.substring(0,5).split(":");
   if(s.equals("AM")){
   //if the time is in AM then we can use same hours and minutes except for 12th hour so we need
   //special case for that if it is 12th hour we will use "00" instead of 12 for other we can use same hours
   if(hoursAndMinutes[0].equals("12")) return "00"+hoursAndMinutes[1];
   else return hoursAndMinutes[0]+hoursAndMinutes[1];
   }
   else{
   //if the time is in PM we need to add hours to 12 unless the hour is 12 in case of 12 we need to keep it as it is
   if(hoursAndMinutes[0].equals("12")) return "12"+hoursAndMinutes[1];
   else{
   int hours=Integer.valueOf(hoursAndMinutes[0]);
   hoursAndMinutes[0]=String.valueOf(12+hours);
   return hoursAndMinutes[0]+hoursAndMinutes[1];
   }
   }
  
   }
}