[SOLVED] calling a boolean method, confusion!!

[AngrYkIdzrUlE]

Im trying to make user enter hours in 24-hours mode then the method "isValidTime" tests if it is in the range of hours between 00 to 23 and the minutes from 00 to 59 and supposed to return the value to allow the code from

while (timeStart > 0) 
		{
			
			
			System.out.print("Enter distance on Kilometres: ");
			int distance = key.nextInt();
			System.out.print("Enter length of call in minutes: ");
			length = key.nextInt();
			
			double costPerCall = total(timeStart, distance, length); // calculates the cost per call
			
			totalCost+=costPerCall;
			numOfCall++;
			
			
			System.out.printf("The call will cost RM %.2f\n", costPerCall);
			
			System.out.println();
			System.out.print("Enter time in 24-hour mode(NEGATIVE integer to quit): ");
			timeStart = key.nextInt();
		}
		
			double AvgCost = Average(totalCost, numOfCall);
			
				if (totalCost == 0)
			{
				System.out.println("No call is made");
			}
				else
			{
				System.out.printf("The total cost for all calls is RM %.2f\n", totalCost);
				System.out.println();
				System.out.printf("The average cost is RM %.2f\n", AvgCost);
			}
	}

to run...please help.


THE WHOLE PROGRAM HERE!!!!

import java.util.Scanner;

public class Tester
{
	public static void main(String[] args)
	{
		Scanner key = new Scanner(System.in);
		
		System.out.print("Enter time in 24-hour mode(NEGATIVE integer to quit): ");
		int timeStart = key.nextInt();
		int numOfCall = 0; // initialise the number of calls made
		double totalCost = 0.0; 
		//int hours = (timeStart/100); // separates the time
		//int minutes = (timeStart%100);
		int length = 0;// initialise the length of call
		
		boolean timeTest = isValidTime(timeStart);
		
		
		//loop begins here
		while (timeStart > 0) 
		{
			
			
			System.out.print("Enter distance on Kilometres: ");
			int distance = key.nextInt();
			System.out.print("Enter length of call in minutes: ");
			length = key.nextInt();
			
			double costPerCall = total(timeStart, distance, length); // calculates the cost per call
			
			totalCost+=costPerCall;
			numOfCall++;
			
			
			System.out.printf("The call will cost RM %.2f\n", costPerCall);
			
			System.out.println();
			System.out.print("Enter time in 24-hour mode(NEGATIVE integer to quit): ");
			timeStart = key.nextInt();
		}
		
			double AvgCost = Average(totalCost, numOfCall);
			
				if (totalCost == 0)
			{
				System.out.println("No call is made");
			}
				else
			{
				System.out.printf("The total cost for all calls is RM %.2f\n", totalCost);
				System.out.println();
				System.out.printf("The average cost is RM %.2f\n", AvgCost);
			}
	}	
	
	public static double total (int time, int distance, int length)  
	{
		double callCost = 0.0;
		//limits 
			if (time >= 700 && time <= 1959) // peak hours
			{
				if (distance > 60) // Trunk (STD) calls
				{
					callCost = 0.50;
				}
				else // local calls
				{
					callCost = 0.20;
				}
			}
			else if (time < 700 || time > 1959) // non-peak hours
			{
				if (distance > 60) // Trunk (STD) calls
				{
					callCost = 0.25; 
				}
				else // local calls
				{
					callCost = 0.10;
				}
			}
				
		double costPerCall = (length*callCost); // calculates the cost for single call.
		return costPerCall;	
	}
	
	public static double Average (double total, int numOfItems)
	{
		double Average = (total/numOfItems);
		return Average;
	}
	
	public static boolean isValidTime(int timeIn)
	{
		int hours = (timeIn/100); // extract hours from 24-hours time 
		int minutes = (timeIn%100); // extract minutes from 24-hours time
		
		{
		if (timeIn >= 0000 || timeIn <= 2359)
			{
		
				if (hours >= 00 || hours <= 23 && minutes >= 00 || minutes <= 59)
					{
						return true;
					}
				else 
				return false;
			}
		else
		return false;
		}
	
	}

}

[Supamagier]

What exactly is your problem? Post error messages or expected/actual output.

[AngrYkIdzrUlE]

What exactly is your problem? Post error messages or expected/actual output.

my problem is i have no idea how to go about doing what i just described... as you can see in my code. Would appreciate the help!

[Eranga]

Actually we cannot say any solution here. Because you had to have a design for that. As an example, say your time format is 12:23, in standard format.

First of all you have to separately find number of hours and number of minutes. Then comparing with the limitation you spoke about.

[AngrYkIdzrUlE]

Actually we cannot say any solution here. Because you had to have a design for that. As an example, say your time format is 12:23, in standard format.

First of all you have to separately find number of hours and number of minutes. Then comparing with the limitation you spoke about.

i did that here

public static boolean isValidTime(int timeIn)
	{
		int hours = (timeIn/100); // extract hours from 24-hours time 
		int minutes = (timeIn%100); // extract minutes from 24-hours time
		
		{

[Eranga]

So what you have to do is compare them with the bound. 00 to 23 for hours and 00 to 59 for minutes.

[AngrYkIdzrUlE]

So what you have to do is compare them with the bound. 00 to 23 for hours and 00 to 59 for minutes.

can you read the code pls. Yes, i did that too....my problem is...calling the return value....can a method have more than one output??

[Eranga]

boolean status = false;

if(hours >= 0 || hours <= 23) {
     status = true;
}

if(minutes >= 0 || minutes <= 59) {
     status = true;
}

return status;

[Eranga]

Did you get the point on the above code?

[AngrYkIdzrUlE]

Did you get the point on the above code?

yeah, thanks...lemme check that out.

[Eranga]

Fine, just look at the logic I've workout. I've not test it, better to workout on it.

[AngrYkIdzrUlE]

Fine, just look at the logic I've workout. I've not test it, better to workout on it.

I did the testing of hours and minutes in one line... like this:

if (hours >= 00 || hours <= 23 && minutes >= 00 || minutes <= 59)
					{
						return true;
					}
				else 
				return false;

[AngrYkIdzrUlE]

does this method make sense???

public static boolean isValidTime(int timeIn)
	{
		boolean vTime= true;
		boolean invTime= true;
		boolean invalTime= true;
		int hours = (timeIn/100); // extract hours from 24-hours time 
		int minutes = (timeIn%100); // extract minutes from 24-hours time
		
		{
		if (timeIn >= 0000 || timeIn <= 2359)
			{
		
				if (hours >= 00 || hours <= 23 && minutes >= 00 || minutes <= 59)
					{
						return true;
					}
				else 
				return false;
			}
		else
		return false;
		}
	
	}

[Eranga]

Ok what happen when you run this code?

This is all about logical operators.

[AngrYkIdzrUlE]

Ok what happen when you run this code?

This is all about logical operators.

sorry, the code should be:

public static boolean isValidTime(int timeIn) // checks if the time format is in 24-hour mode!
	{
		int hours = (timeIn/100);
		int minutes = (timeIn%100);
		
		{
		if (timeIn >= 0000 && timeIn <= 2359)
			{
				if ((hours >= 00 && hours <= 23) && (minutes >= 00 && minutes <= 59))
					return true;
				else
					return false;
			}
		else
				return false;
		}
	
	}

checks for the value entered i.e timeIn if it's in 24-hour mode and returns true and if it's not in 24-hour mode, returns false...

I figured out the problem....thanks all for the input.

[Eranga]

Fine. But my next suggestion is use of SimpleDateFormat. Much stronger and much faster than this way you have workout. And much safer too.

[AngrYkIdzrUlE]

Fine. But my next suggestion is use of SimpleDateFormat. Much stronger and much faster than this way you have workout. And much safer too.

What is SimpleDateFormat??? , can you write it?

[Eranga]

Did you read anything about this on the web? Or else on Java doc?

It's the best way to working on with Date/Time formatting.

[AngrYkIdzrUlE]

Did you read anything about this on the web? Or else on Java doc?

It's the best way to working on with Date/Time formatting.

thanks for that...got it on:

 http://javatechniques.com/blog/dateformat-and-simpledateformat-examples/