8. Mathematical Operations & The Math Class

[!NOTE] Basic operators like +, -, *, / are built securely into Java. But for advanced tasks like absolute values, square roots, and randomness, you utilize the Math class.

The Math Class Toolkit

The Math class contains static methods. This means you do not have to create an object via new Math()—you just access the tools directly!

int maxNumber = Math.max(5, 10);      // returns 10
int minNumber = Math.min(5, 10);      // returns 5
double root = Math.sqrt(64);          // returns 8.0
double absolute = Math.abs(-4.7);     // returns 4.7

  

Generating Random Numbers

One of the most heavily used functions in game development and randomized testing is Math.random().

By default, it returns a double value with a positive sign, greater than or equal to 0.0 and strictly less than 1.0.

double randomNum = Math.random(); // E.g., 0.8273648

  

Controlling the Range

If you want to generate a random integer between 0 and 100, you have to multiply the result and explicitly "cast" the double back down into an int.

// 1. Math.random() generates 0.55// 2. Multiplied by 101 becomes 55.55// 3. The (int) cast chops off the decimals, leaving 55.int randomInt = (int)(Math.random()

101);


  

[!TIP] If you need complex randomization (like Gaussian distributions or robust seeds), look into the java.util.Random class instance approach instead of Math.random().