JavaScript | Math.log1p()

The Math.log1p() is an inbuilt function in JavaScript which gives the value of natural logarithm of 1 + p number. Natural logarithm is of base e, where e is an irrational and transcendental number approximately equal to 2.718.
Syntax:

Math.log1p(1 + p)

    Parameters: In parameter 1+p, p is any number whose natural logarithm of base e is being calculated.

    Returns: It returns the value of base e of logarithm of any number added with 1.

Examples:

Input  : Math.log1p(5)
Output : 1.791759469228055

Explanation:
Here value of natural logarithm of number 5 is 1.791759469228055 as shown output.



Input  : Math.log1p(10)
Output : 2.3978952727983707

Let’s see some JavaScript code on this function:

  • Example 1:
    filter_none

    edit
    close

    play_arrow

    link
    brightness_4
    code

    <script>
      
    // Different numbers are being taken
    // as the parameter of the function.
    document.write(Math.log1p(1000) + "<br>");
    document.write(Math.log1p(12) + "<br>");
    document.write(Math.log1p(26) + "<br>");
    document.write(Math.log1p(5));
      
    </script>

    chevron_right

    
    

    Output:

    6.90875477931522
    2.5649493574615367
    3.295836866004329
    1.791759469228055
  • Example 2:
    filter_none

    edit
    close

    play_arrow

    link
    brightness_4
    code

    <script>
      
    // Taken parameter from 1 to 19 incremented by 3.
    for (i = 1; i < 20; i += 3)
    {
        document.write(Math.log1p(i) + "<br>");
    }
      
    </script>

    chevron_right

    
    

    Output:

    0.6931471805599453
    1.6094379124341003
    2.0794415416798357
    2.3978952727983707
    2.639057329615259
    2.833213344056216
    2.995732273553991
    

Errors and exceptions: Parameters for this function should always be a number otherwise it returns NaN i.e, not a number when its parameter is taken as a string.

  • Example 1:
    filter_none

    edit
    close

    play_arrow

    link
    brightness_4
    code

    <script>
      
        // Parameters for this function should always be a
        // number otherwise it return NaN i.e, not a number
        // when its parameter taken as string.
        document.write(Math.log1p("gfg"));
      
    </script>

    chevron_right

    
    

    Output:

     NaN
    
  • Example 2: This function gives error when its parameter is taken as complex number because it accepts only integer value as the parameter.
    filter_none

    edit
    close

    play_arrow

    link
    brightness_4
    code

    <script>
      
        // Parameters can never be a complex number because
        // it accept only integer value as the parameter.
        document.write(Math.log1p(1 + 2i));
      
    </script>

    chevron_right

    
    

    Output:

    Error: Invalid or unexpected token
    
  • Example 3: This function returns NaN i.e, not a number if the parameter is less than -1 because number should be any positive number i.e, greater then 0.
    filter_none

    edit
    close

    play_arrow

    link
    brightness_4
    code

    <script>
      
        // This function return NaN i.e, not a number
        // if the parameter is less
        // than -1 because number should be
        // any positive number i.e, greater then 0.
        document.write(Math.log1p(-2));
      
    </script>

    chevron_right

    
    

    Output:

     NaN
    

    Application:Whenever we need to find the value of natural logarithm of 1 + p number that time we take the help of this function. Its value needed many times in mathematics problem.
    Let’s see JavaScript code for this application:

  • Example 1:
    filter_none

    edit
    close

    play_arrow

    link
    brightness_4
    code

    <script>
      
        // taking parameter as number 14 and calculated
        // in the form of function.
        function value_of_base_e_logarithms_of_any_number() {
            return Math.log10(14);
        } document.write(value_of_base_e_logarithms_of_any_number());
      
    </script>

    chevron_right

    
    

    Output:

    1.146128035678238

Supported Browsers: The browsers supported by JavaScript Math.log1p( ) function are listed below:

  • Google Chrome
  • Internet Explorer
  • Firefox
  • Opera
  • Safari


My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.