Java Math log()

In this tutorial, we will learn about the Java Math log() method with the help of examples.

The log() method computes the natural logarithm (base e) of the specified value and returns it.

Example

class Main {
  public static void main(String[] args) {

    // compute log() of 9
    System.out.println(Math.log(9.0));


  }
}

// Output: 2.1972245773362196

Syntax of Math.log()

The syntax of the log() method is:

Math.log(double x)

Here, log() is a static method. Hence, we are calling the method directly using the class name Math.

log() Parameters

x - the value whose logarithm is to be computed

log() Return Values

returns the natural logarithm of x (i.e. ln a)
returns NaN if the argument is NaN or less than zero
returns positive infinity if the argument is positive infinity
returns negative infinity if the argument is zero

Example: Java Math.log()

class Main {
  public static void main(String[] args) {

    // compute log() for double value
    System.out.println(Math.log(9.0));       // 2.1972245773362196

    // compute log() for zero
    System.out.println(Math.log(0.0));       // -Infinity


    // compute log() for NaN
    double nanValue = Math.sqrt(-5.0);
    System.out.println(Math.log(nanValue));  // NaN


    // compute log() for infinity
    double infinity = Double.POSITIVE_INFINITY;
    System.out.println(Math.log(infinity));  // Infinity


    // compute log() for negative numbers
    System.out.println(Math.log(-9.0));      // NaN


  }
}

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