java - Always Round UP a Double

Question

How could I always round up a double to an int, and never round it down. I know of Math.round(double), but I want it to always round up. So if it was 3.2, it gets rounded to 4.

Answer 1

You can use Math.ceil() method.

See JavaDoc link: https://docs.oracle.com/javase/10/docs/api/java/lang/Math.html#ceil(double)

From the docs:

ceil

public static double ceil(double a)

Returns the smallest (closest to negative infinity) double value that is greater than or equal to the argument and is equal to a mathematical integer. Special cases:

• If the argument value is already equal to a mathematical integer, then the result is the same as the argument.
• If the argument is NaN or an infinity or positive zero or negative zero, then the result is the same as the argument.
• If the argument value is less than zero but greater than -1.0, then the result is negative zero.

Note that the value of Math.ceil(x) is exactly the value of -Math.floor(-x).

Parameters:

• a - a value.

Returns:

The smallest (closest to negative infinity) floating-point value that is greater than or equal to the argument and is equal to a mathematical integer.