Java Math

Introduction to Java Math

The Java Math class provides a collection of methods to perform mathematical operations such as calculating powers, trigonometric functions, logarithms, rounding, and generating random numbers. The Math class is a part of the java.lang package, so it does not need to be explicitly imported. It contains static methods, which means you can call them directly using the class name.

Key Features of the Math Class

1. No Need for Instantiation:
   Since all methods in the Math class are static, you don’t need to create an object of the Math class to use them.
2. Wide Range of Operations:
   The Math class supports operations like:
   • Basic arithmetic
   • Trigonometry
   • Exponentiation
   • Rounding
   • Random number generation

Commonly Used Methods in the Math Class

Here is a list of important Math methods with examples:

1. Math.abs()

The Math.abs() method returns the absolute (non-negative) value of a number.
Example:

public class MathExample {
    public static void main(String[] args) {
        int num = -10;
        System.out.println("Absolute value: " + Math.abs(num)); // Output: 10
    }
}

2. Math.max() and Math.min()

• Math.max() returns the larger of two numbers.
• Math.min() returns the smaller of two numbers.
  Example:

public class MathExample {
    public static void main(String[] args) {
        int a = 15, b = 20;
        System.out.println("Maximum: " + Math.max(a, b)); // Output: 20
        System.out.println("Minimum: " + Math.min(a, b)); // Output: 15
    }
}

3. Math.sqrt()

The Math.sqrt() method calculates the square root of a number.
Example:

public class MathExample {
    public static void main(String[] args) {
        double num = 16;
        System.out.println("Square root: " + Math.sqrt(num)); // Output: 4.0
    }
}

4. Math.pow()

The Math.pow() method raises a number to the power of another number.
Example:

public class MathExample {
    public static void main(String[] args) {
        double base = 2, exponent = 3;
        System.out.println("2^3: " + Math.pow(base, exponent)); // Output: 8.0
    }
}

5. Math.round(), Math.floor() and Math.ceil()

• Math.round() rounds a number to the nearest whole number.
• Math.floor() rounds a number down to the nearest whole number.
• Math.ceil() rounds a number up to the nearest whole number.

Example:

public class MathExample {
    public static void main(String[] args) {
        double num = 5.7;
        System.out.println("Round: " + Math.round(num));  // Output: 6
        System.out.println("Floor: " + Math.floor(num));  // Output: 5.0
        System.out.println("Ceil: " + Math.ceil(num));    // Output: 6.0
    }
}

6. Math.random()

The Math.random() method generates a random number between 0.0 (inclusive) and 1.0 (exclusive).
Example:

public class MathExample {
    public static void main(String[] args) {
        System.out.println("Random number: " + Math.random());
    }
}

Generating Random Numbers in a Range:

public class MathExample {
    public static void main(String[] args) {
        int min = 1, max = 10;
        int randomNum = (int) (Math.random() * (max - min + 1) + min);
        System.out.println("Random number between 1 and 10: " + randomNum);
    }
}

7. Math.log() and Math.exp()

• Math.log() calculates the natural logarithm (base e) of a number.
• Math.exp() returns e raised to the power of a number.

Example:

public class MathExample {
    public static void main(String[] args) {
        double num = 2;
        System.out.println("Natural log: " + Math.log(num)); // Output: 0.693...
        System.out.println("Exp: " + Math.exp(num));         // Output: 7.389...
    }
}

8. Trigonometric Functions

The Math class provides several methods for trigonometric calculations:

• Math.sin()
• Math.cos()
• Math.tan()

Example:

public class MathExample {
    public static void main(String[] args) {
        double angle = Math.toRadians(45); // Convert degrees to radians
        System.out.println("Sin(45°): " + Math.sin(angle));
        System.out.println("Cos(45°): " + Math.cos(angle));
        System.out.println("Tan(45°): " + Math.tan(angle));
    }
}

9. Math.PI and Math.E

The Math class provides the mathematical constants PI and E.
Example:

public class MathExample {
    public static void main(String[] args) {
        System.out.println("PI: " + Math.PI);
        System.out.println("E: " + Math.E);
    }
}