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.
java
// Java program to demonstrate working // of java.lang.Math.log() method import java.lang.Math;
class GFG {
// driver code
public static void main(String args[])
{
double a = - 2.55 ;
double b = 1.0 / 0 ;
double c = 0 , d = 145.256 ;
// negative integer as argument, output NAN
System.out.println(Math.log(a));
// positive infinity as argument, output Infinity
System.out.println(Math.log(b));
// positive zero as argument, output -Infinity
System.out.println(Math.log(c));
// positive double as argument
System.out.println(Math.log(d));
}
} |
Output:
NaN Infinity -Infinity 4.978497702968366
Example 2:
Java
import java.io.*;
class GFG {
public static void main(String[] args)
{
double number = 10.0 ;
double result = Math.log(number);
System.out.println(result);
}
} |
Output
2.302585092994046