Math.pow, exponentsIn Java we may need to square or cube a number. With Math.pow we raise a number to any exponent. We use an exponentiation function.
If you have ever been in a math course, you already know what Math.pow does. It raises the first number to the power of the second number.
Let us begin with this simple Java program. We square 5, which gives us 25, and we square 3 which yields 9. We print the results.
Math.pow is a double. We can cast this to an int if we know that no data loss due to narrowing will occur.Math.pow.int like 2 (which means square).public class Program {
public static void main(String[] args) {
// Raise 5 to the power of 2.
// ... Then raise 3 to the power of 2.
double result1 = Math.pow(5, 2);
double result2 = Math.pow(3, 2);
// ... Display our results.
System.out.println(result1);
System.out.println(result2);
}
}25.0
9.0With methods we can add abstractions to our programs to make them easier to reason about. For example this program uses a square() method. It wraps a call to Math.pow.
square() than use Math.pow with specific arguments. The performance cost here is minimal or none.public class Program {
static double square(int base) {
// We use Math.pow with a second argument of 2 to square.
return Math.pow(base, 2);
}
public static void main(String[] args) {
// Use square method.
double result1 = square(2);
double result2 = square(3);
double result3 = square(4);
System.out.println(result1);
System.out.println(result2);
System.out.println(result3);
}
}4.0
9.0
16.0With Math.pow we compute power functions. We square and cube numbers. With Math.pow we have a reliable and heavily-tested method in the Java framework to use.