We can use math function floor to get the floor of a number or the largest integer which is equal to or lower than the given number.
So by using floor we can get the floor value of an number.
Here is the syntax.
Math.floor(number)
Let us try with some examples.
document.write (Math.floor(11.257)); // output 11
document.write ("<br>----<br>");
document.write (Math.floor(1.56)); // output 1
document.write ("<br>----<br>");
document.write (Math.floor(-3.564)); // output -4
document.write ("<br>----<br>");
document.write (Math.floor(-7.164)); // output -8
document.write ("<br>----<br>");
Not numeric or blank inputs
We will get output as NaN for all blank and non-numeric inputs.
document.write(Math.floor()); // Output NaN
document.write("<br>");
document.write(Math.floor('abc')); // Output NaN
document.write("<br>");
Difference between floor() and round()
Math.floor() always returns previous lower side integer, where Math.round can return integer value higher or lower than the input value.
Example :
<script>
document.write(Math.round(5.42)+'<br>'); // Output 5
document.write(Math.floor(5.42)+'<br>'); // Output 5
document.write(Math.round(5.67)+'<br>'); // Output 6
document.write(Math.floor(5.67)+'<br>'); // Output 5
document.write(Math.round(-5.42)+'<br>'); // Output -5
document.write(Math.floor(-5.42)+'<br>'); // Output -6
document.write(Math.round(-5.67)+'<br>'); // Output -6
document.write(Math.floor(-5.67)+'<br>'); // Output -6
</script>
We can develop a script to get the floor value of a number
Demo of floor function
You can read the php math floor function
