The static method **`log()`** in java.lang.Math class is used to calculate the #key# natural logarithm: Type of logarithm to the base of the mathematical constant e #key# of an argument. It takes a primitive double type argument `x` and computes $log_{e}(x)$.
# 
## Syntax


```java
static double log(double x)
```


## Parameters
`x`: It takes a number of type double.

## Return value
`log()` will return a natural logarithm of double type.
* The result is `NaN` if the argument value is less than zero or NaN.
* The result is positive infinity (+∞) if the argument value is positive infinity.
* The result is negative infinity (-∞) if the argument value is a positive zero (+0) or a negative zero (-0).

## Code
* *Case #1*: A positive value of type double is supplied as an argument. `log()` will return the natural log.
* *Case #2*: A negative value is passed in and `log()` will return NaN.
* *Case #3*: Positive infinity is supplied as an argument and `log()` will return infinity.
* *Case #4*: Negative infinity is supplied as an argument and `log()` will return NAN.


// Load  math library
import java.lang.Math;
// Main class
class EdPresso{
    public static void main( String args[] ) {
        System.out.println(Math.log(89.3));
    }
}

Case#1

// Load  math library
import java.lang.Math;
// Main class
class EdPresso{
    public static void main( String args[] ) {
        System.out.println(Math.log(-89.3));
    }
}

Case#2

// Load  math library
import java.lang.Math;
// Main class
class EdPresso{
    public static void main( String args[] ) {
        System.out.println(Math.log(Double.POSITIVE_INFINITY));
    }
}

Case#3

// Load  math library
import java.lang.Math;
// Main class
class EdPresso{
    public static void main( String args[] ) {
        System.out.println(Math.log(Double.NEGATIVE_INFINITY));
    }
}

Case#4

What is the Math log() function in Java?

Calculates the natural logarithm of a double. Returns NaN for negatives and ∞ for positive infinity.