CODEWITHSUNDEEP
javaexception
Tmanzz122
Tmanzz122

Reputation: 17

Unreachable Java code

When I try to complie this code, Lines 41-45 give me an "Unreachable code" statement. Same thing happens when I put in a few lines to handle exceptions. Is there something wrong that I am doing? This is a modified example code from the book SAMS Teach yourself Java in 24 hours. Using it as a refresher.

import java.util.*;
import java.util.concurrent.TimeUnit;
public class Clock {

public static void main(String[] arguments) {
    Calendar now = Calendar.getInstance();
    int hour = now.get(Calendar.HOUR_OF_DAY);
    int minute = now.get(Calendar.MINUTE);
    int month = now.get(Calendar.MONTH) + 1;
    int day = now.get(Calendar.DAY_OF_MONTH);
    int year = now.get(Calendar.YEAR);

    //Display greeting
    if (hour < 12){
        System.out.println("Good Morning! \n");
    }else if (hour < 17){
        System.out.println("Good afternoon! \n");
    } else {
        System.out.println("Good evening! \n");
    }
    //Time message start
    while(1 < 2){
         try
            {
                final String os = System.getProperty("os.name");

                if (os.contains("Windows"))
                {
                    Runtime.getRuntime().exec("cls");
                }
                else
                {
                    Runtime.getRuntime().exec("clear");
                }
            }
            catch (final Exception e)
            {
                //  Handle any exceptions.
            }
        }
//Errors occur here
        try { 
            TimeUnit.SECONDS.sleep(100);
        }   catch (InterruptedException e) {
            //Handle exception
            }
//Errors end here
            System.out.println("The time currently is:" + hour + ":" + minute);
            System.out.println("Date: " + month + "/" + day + "/" + year);
        }
    }

Upvotes: 1

Views: 267

Answers (5)

lewtenantDan
lewtenantDan

Reputation: 1

You have an infinite loop. 1 is always less than 2.

Suggestions:

  1. Use while(true) and set breaks
  2. Don't put your try/catch in a loop at all. It is only performing one check and the loop seems unnecessary.

Upvotes: 0

optimus_Prime
optimus_Prime

Reputation: 21

As your while loop is an infinite loop, so your code will never reach to your this block. 

//Errors occur here
    try { 
        TimeUnit.SECONDS.sleep(100);
    }   catch (InterruptedException e) {
        //Handle exception
        }
//Errors end here
        System.out.println("The time currently is:" + hour + ":" + minute);
        System.out.println("Date: " + month + "/" + day + "/" + year);
    }

As your code

while(1 < 2){
     try
        {
            final String os = System.getProperty("os.name");

            if (os.contains("Windows"))
            {
                Runtime.getRuntime().exec("cls");
            }
            else
            {
                Runtime.getRuntime().exec("clear");
            }
        }
        catch (final Exception e)
        {
            //  Handle any exceptions.
        }
    } // from here again start from loop staring point and looping this again and again

so in compile time compiler is warning you that your second try block and rest statements are unreachable. you program will never able to execute this blocks. That's why it is saying unreachable.

Upvotes: 0

James Wierzba
James Wierzba

Reputation: 17538

You have a infinite loop with no break statement.

Upvotes: 0

M A
M A

Reputation: 72844

The while loop will never break since 1 < 2 is always true. Therefore, the part after the while loop will never be reached, hence the compiler error.

Upvotes: 2

eric.m
eric.m

Reputation: 1612

The code there is unreachable, as the while loop condition, 1 < 2, is always true, and so you are always in the while loop. To avoid it, you can:

  • Change the while loop condition to something that can be false.
  • Add a break statement somewhere in your while loop, to exit it.

Upvotes: 6

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