# Java - Math log(double) Method

## Description

The Java Math log(double a) returns the natural logarithm (base e) of a double value. Special 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.

## Declaration

Following is the declaration for java.lang.Math.log() method

```public static double log(double a)
```

a − a value

## Return Value

This method returns the value ln a, the natural logarithm of a.

NA

## Getting Log of a Positive Double Value Example

The following example shows the usage of Math log() method.

```package com.tutorialspoint;

public class MathDemo {

public static void main(String[] args) {

// get a double number
double x = 10.7;

// print the log of the number
System.out.println("Math.log(" + x + ")=" + Math.log(x));
}
}
```

## Output

Let us compile and run the above program, this will produce the following result −

```Math.log(10.7)=2.3702437414678603
```

## Getting Log of a Zero Double Value Example

The following example shows the usage of Math log() method of zero value.

```package com.tutorialspoint;

public class MathDemo {

public static void main(String[] args) {

// get a double number
double x = 0.0;

// print the log of the number
System.out.println("Math.log(" + x + ")=" + Math.log(x));
}
}
```

## Output

Let us compile and run the above program, this will produce the following result −

```Math.log(0.0)=-Infinity
```

## Getting Log of a Negative Double Value Example

The following example shows the usage of Math log() method of a negative number.

```package com.tutorialspoint;

public class MathDemo {

public static void main(String[] args) {

// get a double number
double x = -10.7;

// print the log of the number
System.out.println("Math.log(" + x + ")=" + Math.log(x));
}
}
```

## Output

Let us compile and run the above program, this will produce the following result −

```Math.log(-10.7)=NaN
```
java_lang_math.htm