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# StrictMath log() Method In Java

• Last Updated : 23 Jul, 2018

The Java.lang.StrictMath.log() is an inbuilt method of StrictMath class which is used to calculate the natural logarithm i.e., log with base e, of a given double value. It gives rise to three special results:

• It returns a positive infinity when the argument is positive infinity.
• It returns NaN when the argument is NaN or less than zero.
• The result is negative infinity when the argument is positive zero or negative zero.

Syntax:

`public static double log(double num)`

Parameters: The method accepts one parameter num of double type whose logarithmic value is to be found.

Return Value: The method returns the value of natural logarithm of num.

Examples :

```Input: num = 5.0
Output: 1.6094379124341003

Input: num = 10.0
Output:  2.302585092994046
```

Below programs illustrate the Java.lang.StrictMath.log() Method:
Program 1:

 `// Java praogram to illustrate the``// Java.lang.StrictMath.log() Method``import` `java.lang.*;`` ` `public` `class` `Geeks {`` ` `public` `static` `void` `main(String[] args) {`` ` `    ``double` `num1 = ``10` `, num2 = ``25.2` `;``     ` `    ``// It returns natural logarithm(base e) ``    ``double` `log_Value = StrictMath.log(num1); ``    ``System.out.print(``"Log value of "` `+ num1 + ``" = "` `);``    ``System.out.println(log_Value);`` ` `    ``log_Value = StrictMath.log(num2); ``    ``System.out.print(``"Log value of "` `+ num2 + ``" = "` `);``    ``System.out.println(log_Value);`` ` `}``}`
Output:
```Log value of 10.0 = 2.302585092994046
Log value of 25.2 = 3.2268439945173775
```

Program 2:

 `// Java praogram to illustrate the``// Java.lang.StrictMath.log() Method``import` `java.lang.*;`` ` `public` `class` `Geeks {`` ` `public` `static` `void` `main(String[] args) {`` ` `    ``double` `num1 = ``0` `, num2 = (``1.0``/``0.0``) , num3 = ``1``;``     ` `    ``// It returns natural logarithm(base e) ``    ``double` `log_Value = StrictMath.log(num1); ``    ``System.out.print(``"Log value of "` `+ num1 + ``" = "` `);``    ``System.out.println(log_Value);``     ` `    ``log_Value = StrictMath.log(num2); ``    ``System.out.print(``"Log value of "` `+ num2 + ``" = "` `);``    ``System.out.println(log_Value);``     ` `    ``log_Value = StrictMath.log(num3); ``    ``System.out.print(``"Log value of "` `+ num3 + ``" = "` `);``    ``System.out.println(log_Value);`` ` `}``}`
Output:
```Log value of 0.0 = -Infinity
Log value of Infinity = Infinity
Log value of 1.0 = 0.0
```

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