JavaScript | Math.floor() function

The Math.floor() function in JavaScript is used to round off the number passed as a parameter to its nearest integer in Downward direction of rounding i.e. towards the lesser value.

Syntax

Math.floor(value)

Parameters: This function accepts a single parameter value which is number to be rounded to its nearest integer in downward rounding method.
Returns: Result after rounding the number passed as a parameter to the function.passed as parameter.
Example:



Input  : Math.floor(4.23)
Output : 4

Input  : Math.floor(0.8)
Output : 0

Errors and Exceptions:

  • A non-numeric string passed as parameter returns NaN
  • An array with more than 1 integer passed as parameter returns NaN
  • An empty variable passed as parameter returns NaN
  • An empty string passed as parameter returns NaN
  • An empty array passed as parameter returns NaN

Below are some examples that illustrate the Math.floor() function in JavaScript:
Example 1:

filter_none

edit
close

play_arrow

link
brightness_4
code

<script type="text/javascript">
    document.write(Math.floor(-2) + "<br>"); 
    document.write(Math.floor(-2.56));          
</script>

chevron_right


Output:

-2
-3

Example 2:

filter_none

edit
close

play_arrow

link
brightness_4
code

<!-- POSITIVE NUMBER EXAMPLE -->
<script type="text/javascript">
    document.write(Math.floor(2) + "<br>"); 
    document.write(Math.floor(2.56));          
</script>

chevron_right


Output:

2
2

Example 3:

filter_none

edit
close

play_arrow

link
brightness_4
code

<!-- STRING EXAMPLE -->
<script type="text/javascript">
    document.write(Math.floor("Geeksforgeeks"));          
</script>

chevron_right


Output:

NaN

Example 4:

filter_none

edit
close

play_arrow

link
brightness_4
code

<!-- ADDITION INSIDE FUNCTION EXAMPLE -->
<script type="text/javascript">
    document.write(Math.floor(7.2+9.3));           
</script>

chevron_right


Output:

16

Supported Browsers: The browsers supported by JavaScript Math.floor( ) 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.