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Thread: Simple Help
 01092010, 05:58 PM #1Member
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Simple Help
Hello All!
I am new to Java and hope to learn this over time and progress onto EE and ME for future developments.
I am still learning Java syntax basics.
Below is some code I have written, but found when using a single line variable it gives me the wrong answer. I decided to do this with multiple variables and get the correct answer, now I have managed to problem solve the single line variable with stepping the code and found the divide is where my problems start.
Java Code:public class Temperature { public int fahrenheit = 9; public int celsius1 = fahrenheit  32; public int celsius2 = celsius1 * 5; public int celsius3 = celsius2 / 9; public int celsius = fahrenheit  32 * 5 / 9; // public double celsius = fahrenheit(double)  32 * 5 / 9; public void calculateCelsius() { System.out.println(fahrenheit + "Fahrenheit to Celsius is " + celsius3 + "c is correct"); System.out.println(fahrenheit + " Fahrenheit to Celsius is " + celsius + "c"); } }
I don't want to move on in learning until I understand the problem and what I did wrong.
Any help welcomed :)Last edited by Andy_M; 01092010 at 06:00 PM. Reason: Update
 01092010, 06:04 PM #2
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You have been bitten by the 'integer division' operator. That operator divides two ints and forgets all about the remainder. Literal numbers that don't contain a decimal point (a dot) are interpreted as ints by the compiler, so 5/9 is an integer division of the two int numbers 5 and 9; the result is 0 (that forgotten remainder, remember?).
Better use double numbers, e.g. 5.0/9.0 and use variables of type double. Try it and see for yourself.
kind regards,
Jos
 01092010, 06:08 PM #3
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Java Code:public double celsius = (fahrenheit  32) * 5.0 / 9.0;
kind regards,
Jos
 01092010, 06:12 PM #4Member
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Jos,
This has worked a treat. So the game is to make sure I try and use double numbers IE 1.0 for doubles and make sure I close in calculation with ( ) before a higher operator?
 01092010, 07:45 PM #5
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 01092010, 08:06 PM #6Member
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Thank you Jos for taking time out to help me
 01092010, 09:10 PM #7
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