Java Math Class

The Java Math class contains methods for performing basic numeric operations such as the elementary exponential, logarithm, square root, and trigonometric functions.

It is located in the java.lang package, so no import is needed. All methods in the Math class are static.

Basic Math Methods

1. Math.max(x, y)

Returns the number with the highest value.

System.out.println(Math.max(5, 10)); // Outputs 10

2. Math.min(x, y)

Returns the number with the lowest value.

System.out.println(Math.min(5, 10)); // Outputs 5

3. Math.sqrt(x)

Returns the square root of x.

System.out.println(Math.sqrt(64)); // Outputs 8.0

4. Math.abs(x)

Returns the absolute (positive) value of x.

System.out.println(Math.abs(-4.7)); // Outputs 4.7

5. Math.random()

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

System.out.println(Math.random());

To get a random number between 0 and 100:

int randomNum = (int)(Math.random() * 101);  // 0 to 100
System.out.println(randomNum);

Rounding Methods

Math.round()

Rounds to the nearest integer.

System.out.println(Math.round(24.5)); // 25
System.out.println(Math.round(24.4)); // 24

Math.ceil()

Rounds up to the nearest integer (returned as double).

System.out.println(Math.ceil(24.1)); // 25.0

Math.floor()

Rounds down to the nearest integer (returned as double).

System.out.println(Math.floor(24.9)); // 24.0

Exponential and Logarithmic Methods

Math.pow(base, exponent)

Returns the value of the first argument raised to the power of the second argument.

System.out.println(Math.pow(2, 3)); // 2^3 = 8.0

Math.exp(x)

Returns Euler's number e raised to the power of x.

Math.log(x)

Returns the natural logarithm (base e) of x.

Math.log10(x)

Returns the base 10 logarithm of x.

Trigonometric Methods

Angles are measured in radians.

• Math.sin(angle)
• Math.cos(angle)
• Math.tan(angle)
• Math.toDegrees(radians)
• Math.toRadians(degrees)

double angle = 45;
double radians = Math.toRadians(angle);
System.out.println(Math.sin(radians));

Constants

The Math class provides two useful constants:

1. Math.PI: The ratio of the circumference of a circle to its diameter (approx 3.14159).
2. Math.E: The base of the natural logarithms (approx 2.71828).

System.out.println(Math.PI);
System.out.println(Math.E);

Key Takeaways

• Static Methods: You call them directly on the class, e.g., Math.max().
• Precision: Most methods return double for precision.
• Random: Math.random() is useful for generating simple random numbers.
• Constants: Use Math.PI and Math.E for high-precision constants.