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JavaScript: Math log2() function

This JavaScript tutorial explains how to use the math function called log2() with syntax and examples.

Description

In JavaScript, log2() is a function that is used to return the base-2 logarithm of a number. Because the log2() function is a static function of the Math object, it must be invoked through the placeholder object called Math.

Syntax

In JavaScript, the syntax for the log2() function is:

Math.log2(number);

Parameters or Arguments

number
The number to use in the calculation. It must be a value that is greater than 0.

Returns

The log2() function returns the base-2 logarithm of a number.

If the number is 0, the log2() function will return -Infinity.

If the number is a negative value, the log2() function will return NaN.

Note

  • Math is a placeholder object that contains mathematical functions and constants of which log2() is one of these functions.

Example

Let's take a look at an example of how to use the log2() function in JavaScript.

For example:

console.log(Math.log2(1));
console.log(Math.log2(2.5));
console.log(Math.log2(0));
console.log(Math.log2(-4));

In this example, we have invoked the log2() function using the Math class.

We have written the output of the log2() function to the web browser console log, for demonstration purposes, to show what the log2() function returns.

The following will be output to the web browser console log:

0
1.3219280948873624
-Infinity
NaN

In this example, the first output to the console log returned 0 which is the base-2 logarithm of 1.

The second output to the console log returned 1.3219280948873624 which is the base-2 logarithm of 2.5.

The second output to the console log returned -Infinity since the number provided was 0.

The second output to the console log returned NaN since the number provided was a negative value.

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