JavaScript Math floor()

In this tutorial, we will learn about the JavaScript Math.floor() function with the help of examples.

The Math.floor() function rounds down a number to the next smallest integer.


let number = 38.8;

// round number to nearest smallest number let roundedNumber = Math.floor(number);
console.log(roundedNumber); // Output: 38

Math.floor() Syntax

The syntax of the Math.floor() function is:


floor(), being a static method, is called using the Math class name.

Math.floor() Parameters

The Math.floor() function takes in:

  • x - A number

Math.floor() Return Value

  • Returns the largest integer less than or equal to a given number.
  • Returns 0 for null.

Example: Using Math.floor()

// using Math.floor()

var num = Math.floor(1.8645);
console.log(num); // 1 var num = Math.floor(-0.456); console.log(num); // -1
var num = Math.floor("4");
console.log(num); // 4
// Returns 0 for null var num = Math.floor(null);
console.log(num); // 0
// Returns NaN for non-numeric types var num = Math.floor("JavaScript");
console.log(num); // NaN var num = Math.floor(NaN); console.log(num); // NaN



Note: Math.floor() returns 0 for null rather than NaN.

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