Java Math

The Java Math class has many methods that allows you to perform mathematical tasks on numbers.

Math.max(x,y)

The Math.max(x,y) method can be used to find the highest value of x and y:

Math.max(5, 10);

Math.min(x,y)

The Math.min(x,y) method can be used to find the lowest value of x and y:

Math.min(5, 10);

Math.sqrt(x)

The Math.sqrt(x) method returns the square root of x:

Math.sqrt(64);

Math.abs(x)

The Math.abs(x) method returns the absolute (positive) value of x:

Math.abs(-4.7);

Math.pow(x, y)

The Math.pow(x, y) method returns the value of x raised to the power of y:

Math.pow(2, 8);  // 256.0

Rounding Methods

Java has several methods for rounding numbers:

• Math.round(x) - rounds to the nearest integer
• Math.ceil(x) - rounds up (returns the smallest integer greater than or equal to x)
• Math.floor(x) - rounds down (returns the largest integer less than or equal to x)

Math.round(4.6);  // 5
Math.ceil(4.1);   // 5.0
Math.floor(4.9);  // 4.0

Random Numbers

Math.random() returns a random number between 0.0 (inclusive), and 1.0 (exclusive):

Math.random();

To get more control over the random number, for example, if you only want a random number between 0 and 100, you can use the following formula:

int randomNum = (int)(Math.random() * 101);  // 0 to 100