Java Math

The Math class in Java is a utility class that offers several static methods for basic mathematical operations.

It belongs to the java.lang package, so you don’t need to import it explicitly.

The methods in the Math class are designed to handle common tasks, including rounding, exponentiation, logarithmic calculations, trigonometric functions, and generating random numbers.

Arithmetic Functions

There are many arithmetic functions, such as abs(double a), abs(int a), max(double a, double b), and min(double a, double b).

public class ArithmeticMathExample {
    public static void main(String[] args) {
        System.out.println("Absolute value of -15.4: " + Math.abs(-15.4));  // 15.4
        System.out.println("Absolute value of -7: " + Math.abs(-7));        // 7
        System.out.println("Max of 15.4 and 25.5: " + Math.max(15.4, 25.5));  // 25.5
        System.out.println("Min of 15.4 and 25.5: " + Math.min(15.4, 25.5));  // 15.4
    }
}

Rounding Functions

There are many round functions

round(float a), round(double a)

Rounds the input to the closest integer. If the input is exactly halfway between two integers, it rounds up.

public class MathRoundExample {
    public static void main(String[] args) {
        System.out.println("Round of 4.7f: " + Math.round(4.7f));  // 5
        System.out.println("Round of 5.3: " + Math.round(5.3));    // 5
        System.out.println("Round of 5.5: " + Math.round(5.5));    // 6
    }
}

ceil(double a)

Rounds the input up to the nearest whole number, even if it’s already a whole number.

public class MathCeilExample {
    public static void main(String[] args) {
        System.out.println("Ceil of 5.4: " + Math.ceil(5.4));  // 6.0
        System.out.println("Ceil of 5.9: " + Math.ceil(5.9));  // 6.0
    }
}

floor(double a)

Rounds the number down to the nearest whole number.

public class MathFloorExample {
    public static void main(String[] args) {
        System.out.println("Floor of 5.4: " + Math.floor(5.4));  // 5.0
        System.out.println("Floor of 5.9: " + Math.floor(5.9));  // 5.0
    }
}

Random Number Generation

Returns a random number between 0.0 (inclusive) and 1.0 (exclusive)

public class MathRandomExample {
    public static void main(String[] args) {
        double randomValue = Math.random();
        System.out.println("Random number between 0.0 and 1.0: " + randomValue);
    }
}

Generate a random integer between min and max

Suppose, we have min value is 0 and max value is 100

public class MathRandomExample {
    public static void main(String[] args) {
        int min = 1;
        int max = 100;
        double randomValue =  (int)(Math.random() * (max - min + 1)) + min;
        System.out.println("Random number between 0 and 100: " + randomValue);
    }
}

Mathematical Constants

The Math class defines a some useful constants:

1. Math.PI: The value of π (approximately 3.14159).
2. Math.E: The value of Euler’s number e (approximately 2.71828).

Example:

public class MathConstantsExample {
    public static void main(String[] args) {
        System.out.println("Value of Pi: " + Math.PI);
        System.out.println("Value of Euler's number: " + Math.E);
    }
}

Output: