Java double Example

Category: Basics   November 26, 2012

Have you ever met the situation that you get an integer but you really want a double?

For the following method, devide(2,3) will return 0.0.

public static double devide(int x, int y){
	return x/y;
}

The problem is that x/y does int division. If you want it to do double division, you can cast one of the operands. Both (double)x/y and x/(double)y will work.

public static double devide(int x, int y){
	return (double)x/y;
}

Very often you may want to round a double number. There are multiple ways to do it and the following is a commonly used simple method. If you want to round the result to 2 digits, you can use the following code:

public static double divide(int x, int y){
	double z= (double)x/y;
	double pro = Math.round(z * 100);
	return pro/100;
}

Related posts:

  1. Syntactic vs. Semantic vs. Runtime Errors
  2. Interview Question – Use Java Thread to Do Math Calculation
  3. Sort a Double LinkedList in Java
  4. Double star after type and before variable
Category >> Basics  
If you want someone to read your code, please put the code inside <pre><code> and </code></pre> tags. For example: 
<pre><code> 
String foo = "bar";
</code></pre>