Math Class

// No import needed — Math is in java.lang
// No object creation needed — all methods are static
double result = Math.sqrt(25);  // 5.0

System.out.println(Math.abs(-15));    // 15
System.out.println(Math.abs(15));     // 15
System.out.println(Math.abs(-3.7));   // 3.7
System.out.println(Math.abs(0));      // 0

int a = 10, b = 3;
int distance = Math.abs(a - b);  // 7

System.out.println(Math.pow(2, 3));    // 8.0
System.out.println(Math.pow(5, 2));    // 25.0
System.out.println(Math.pow(10, 0));   // 1.0
System.out.println(Math.pow(4, 0.5));  // 2.0 (same as square root)

int result = (int) Math.pow(2, 10);  // 1024

System.out.println(Math.sqrt(25));   // 5.0
System.out.println(Math.sqrt(2));    // 1.4142135623730951
System.out.println(Math.sqrt(0));    // 0.0

double a = 3, b = 4;
double c = Math.sqrt(Math.pow(a, 2) + Math.pow(b, 2));
System.out.println("Hypotenuse: " + c);  // 5.0

double r = Math.random();  // e.g., 0.7342...

// Roll a standard die (1-6)
int die = (int)(Math.random() * 6) + 1;

// Random number from 25 to 50
int num = (int)(Math.random() * 26) + 25;
// range = 50 - 25 + 1 = 26

// Static — called on the class
double root = Math.sqrt(9);       // Math.method()

// Non-static — called on an object
String s = "hello";
int len = s.length();              // object.method()

public class DistanceCalculator {
    public static void main(String[] args) {
        // Two points on a coordinate plane
        double x1 = 1, y1 = 2;
        double x2 = 4, y2 = 6;
        
        // Distance formula: sqrt((x2-x1)^2 + (y2-y1)^2)
        double distance = Math.sqrt(
            Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2)
        );
        
        System.out.println("Distance: " + distance);  // 5.0
        
        // Round to 2 decimal places
        double rounded = (int)(distance * 100) / 100.0;
        System.out.println("Rounded: " + rounded);
    }
}