Java Math Class: Numerical Methods & Random Number Generation

The java.lang.Math class contains a comprehensive suite of static mathematical methods for performing basic numeric calculations, logarithms, square roots, and trigonometric calculations.

Essential java.lang.Math Methods

public class MathDemo {
    public static void main(String[] args) {
        // Mathematical Constants:
        System.out.println("PI: " + Math.PI); // 3.141592653589793
        System.out.println("E:  " + Math.E);  // 2.718281828459045

        // Fundamental Functions:
        System.out.println("Absolute:    " + Math.abs(-45));       // 45
        System.out.println("Max (10,20): " + Math.max(10, 20));    // 20
        System.out.println("Min (10,20): " + Math.min(10, 20));    // 10
        System.out.println("Power (2^8): " + Math.pow(2, 8));      // 256.0
        System.out.println("Square Root: " + Math.sqrt(81));       // 9.0

        // Rounding Functions:
        System.out.println("Ceil (4.1):  " + Math.ceil(4.1));      // 5.0 (Rounds UP)
        System.out.println("Floor (4.9): " + Math.floor(4.9));     // 4.0 (Rounds DOWN)
        System.out.println("Round (4.5): " + Math.round(4.5));     // 5 (Nearest int)
    }
}

Generating Random Numbers in a Specific Range

To generate an integer between min and max (inclusive) using Math.random():

// Formula: (int)(Math.random() * (max - min + 1)) + min
int min = 10;
int max = 50;
int randomNum = (int)(Math.random() * (max - min + 1)) + min;
System.out.println("Random Number between 10 and 50: " + randomNum);