Java Math

Finding the Bigger or Smaller Value

Math.max() returns the larger of two numbers and Math.min() returns the smaller. Both accept two values of the same type and are perfect when you need to keep a value within a range or pick a winner between two options.

System.out.println(Math.max(8, 15));  // 15
System.out.println(Math.min(8, 15));  // 8
System.out.println(Math.max(-4, -9)); // -4

Powers, Roots, and Absolute Values

Math.pow() raises a number to a power, Math.sqrt() computes a square root, and Math.abs() gives the distance of a number from zero, always as a positive value. These three cover a large share of everyday number crunching.

System.out.println(Math.pow(2, 5)); // 32.0
System.out.println(Math.sqrt(144)); // 12.0
System.out.println(Math.abs(-7));   // 7

Rounding Numbers

Java offers three ways to round. Math.round() moves to the nearest whole number, Math.ceil() always rounds up, and Math.floor() always rounds down. The table shows how each one treats the same input.

Random Numbers

Math.random() returns a double from 0.0 up to (but not including) 1.0. To get a whole number in a range, multiply by the range size, cast to int, and shift as needed. The example produces a value from 1 to 6, like a dice roll.

int roll = (int) (Math.random() * 6) + 1;
System.out.println("You rolled: " + roll); // 1 to 6

• Every Math method is static, so call it as Math.methodName().
• Math.pow(), Math.sqrt(), Math.ceil(), and Math.floor() return a double.
• Math.PI and Math.E are handy built-in constants for geometry and growth formulas.
• For repeated or more flexible random numbers, the java.util.Random class is a good alternative.