The java.lang.Math.log() method returns the natural logarithm (base e) of a double value as a parameter. There are various cases :
- If the argument is NaN or less than zero, then the result is NaN.
- If the argument is positive infinity, then the result is positive infinity.
- If the argument is positive zero or negative zero, then the result is negative infinity.
Syntax :
public static double log(double a)
Parameter :
a : User input
Return Type:
This method returns the value ln a.
Example 1: To show the working of java.lang.Math.log() method.Â
java
// Java program to demonstrate working// of java.lang.Math.log() methodÂ
import java.lang.Math;Â
class GFG {Â
    // driver code    public static void main(String args[])    {        double a = -2.55;        double b = 1.0 / 0;        double c = 0, d = 145.256;Â
        // negative integer as argument, output NAN        System.out.println(Math.log(a));Â
        // positive infinity as argument, output Infinity        System.out.println(Math.log(b));Â
        // positive zero as argument, output -Infinity        System.out.println(Math.log(c));Â
        // positive double as argument        System.out.println(Math.log(d));    }} |
Output:
NaN Infinity -Infinity 4.978497702968366
Example 2:
Java
import java.io.*;Â
class GFG {Â Â Â Â public static void main(String[] args)Â Â Â Â {Â Â Â Â Â Â Â Â double number = 10.0;Â Â Â Â Â Â Â Â double result = Math.log(number);Â Â Â Â Â Â Â Â System.out.println(result);Â Â Â Â }} |
Output
2.302585092994046
