Question

In JAVA Write a program that converts a time from 24-hour notation to 12-hour notation. Assume the user will enter the time as a 4-digit number with no colon.

Define an exception class called InvalidTimeFormatException. If the user enters an invalid time lime 1065 or 2515, the program should throw and handle an InvalidTimeFormatException. NOTE: Assume the user will enter the time as a 4-digit number with no colon.

SAMPLE OUTPUT:

Enter time in 24-hour notation:

1614

That is the same as 4:14pm

Again? (y/n)

y

Enterprise in a 24-hour notation:

0245

That is the same as 2:45 AM

Again?(y/n)

Answer 1

Code:

//importing this package because we are using scanner class
import java.util.*;
//exception class
class InvalidTimeFormatException extends Exception{
   //construcotr
   InvalidTimeFormatException(String s){
       super(s);
   }
}
//class named time, the file should be named as Time.java
class Time {
   //main method
   public static void main(String[] args){
       //creating an instance of scanner class
       Scanner s = new Scanner(System.in);
       //an infinite loop which only breaks when user enters n
       while(true){
           //taking input
       System.out.println("Enter time in 24- hour notation: ");
       int t=s.nextInt();
       //try block
       try{
       //string str to store output
       String str="";
       //getting houts and mins from input
       int hr=t/100;
       int min=t%100;
       //if user enters invalid time throwing exception
       if(hr >24 || min>60){
           throw new InvalidTimeFormatException("Exception occured");
       }
       //if hr is greater than 12
       //subtracting 12 from hr and adding Pm at the end
       if(hr>12 && hr<=24){
           hr=hr-12;
           str=hr+":"+min+" PM";

       }
       //else adding AM at the end
       else{
           str=hr+":"+min+" AM";

       }
       //printing output
       System.out.println("The time is: "+str);
       //catching exception
   }catch(InvalidTimeFormatException i){
       System.out.println(i);
   }
   //taking choice
   System.out.println("Again?(y/n):");
   char ch= s.next().charAt(0);
   //if the choice is n , breaking the loop
   if(ch=='N' || ch =='n'){
       break;
   }
   }
}
}

Output:

Code Screenshot:

Code Snippet:

//importing this package because we are using scanner class
import java.util.*;
//exception class
class InvalidTimeFormatException extends Exception{
        //construcotr
        InvalidTimeFormatException(String s){
                super(s);
        }
}
//class named time, the file should be named as Time.java
class Time {
        //main method
        public static void main(String[] args){
                //creating an instance of scanner class
                Scanner s = new Scanner(System.in);
                //an infinite loop which only breaks when user enters n
                while(true){
                        //taking input
                System.out.println("Enter time in 24- hour notation: ");
                int t=s.nextInt();
                //try block
                try{
                //string str to store output
                String str="";
                //getting houts and mins from input
                int hr=t/100;
                int min=t%100;
                //if user enters invalid time throwing exception
                if(hr >24 || min>60){
                        throw new InvalidTimeFormatException("Exception occured");
                }
                //if hr is greater than 12 
                //subtracting 12 from hr and adding Pm at the end
                if(hr>12 && hr<=24){
                        hr=hr-12;
                        str=hr+":"+min+" PM";

                }
                //else adding AM at the end
                else{
                        str=hr+":"+min+" AM";

                }
                //printing output
                System.out.println("The time is: "+str);
                //catching exception
        }catch(InvalidTimeFormatException i){
                System.out.println(i);
        }
        //taking choice 
        System.out.println("Again?(y/n):");
        char ch= s.next().charAt(0);
        //if the choice is n , breaking the loop
        if(ch=='N' || ch =='n'){
                break;
        }
        }
}
}

Note:

Save the file name as Time.java