Math.pow in Java
In this quick post, we will get an understanding of Math.pow in Java. power of the number in a simple term shows how many times to use a number for multiplication.
1. Math.pow Example
Math.pow
have a simple signature like
public static double pow(double a, double b)
, where 'a'
indicates the base, 'b'
indicated the exponent and Math.pow()
will return the value as
a<sup>b</sup>
Let’s look into a simple example to understand how Mah.pow works.
@Test
public void calculateIntPow(){
int a= 3;
int b=4;
int result = (int) Math.pow(a,b);
assertEquals(81, result);
}
Since we were expecting results in an int, it was required to cast the output to int to get desired results. It does not require us to cast results in case desired output is in double (which is also output for of the Math.pow()
method)
@Test
public void calculateDoublePow(){
double a= 3.4;
int b=4;
double result = Math.pow(a,b);
assertEquals(133.63, result, 2);
}
There are certain features/properties of this method, read Math.pow for more detail.
2. Xor and Pow
Xor and Pow are different and they can create confusion. When we write a<sup>b</sup>
, we follow below syntax
Mathematics
2^3 = 2x2x2 = 8
// Using Math.pow
Math.pow(2, 3)
In Java, ^
is known as xor operator which differs from the power operation. Let’s look at the following example for more details.
package com.javadevjournal;
import org.junit.Test;
import static org.junit.Assert.assertEquals;
public class MathPowXorTest {
private static final double DELTA = 0.001 d;
@Test
public void xorOperatorTest() {
assertEquals(8 d, Math.pow(2 d, 3 d), DELTA);
assertEquals(7 d, 2 ^ 5, DELTA);
}
}
Summary
In this quick post, we get an understanding how to Use the Math.pow method in Java to calculate the power of any base.