# JavaScript Math.log2()

The `Math.log2()` method returns the base 2 logarithm of a number. It is equivalent to log2(x) in mathematics.

### Example

``````// calculate the base 2 log of 2
let value= Math.log2(2);

console.log(value)

// Output: 1``````

## log2() Syntax

The syntax of `log2()` is:

``Math.log2(x)``

Here, `log2()` is a static method. Hence, we need to access the method using the class name, `Math`.

## log2() Parameters

The `log2()` method takes in:

• x - a number

## log2() Return Values

The `log2()` method returns:

• the base 2 logarithm of the given number.
• `NaN` for negative numbers and non-numeric arguments.

## Example 1: JavaScript Math.log2()

``````// find the base 2 log value of 1
var value1 = Math.log2(1);
console.log(value1);

// find the base 2 log value of 8
var value2=Math.log2(8);
console.log(value2)``````

Output

```0
3```

In the above example,

• `Math.log2(1)` - computes the base 2 log value of 1
• `Math.log2(8)` - computes the base 2 log value of 8

## Example 2: log2() With 0

``````
// find the base 2 log value of 0
var value = Math.log2(0);

console.log(value);

// Output: -Infinity``````

In the above example, we have used the `log2()` method to compute the base 2 log value of 0.

The output `-Infinity` indicates that the base 2 log value of 0 is negative infinity.

## Example 3: log2() With Negative Values

``````// find the base 2 log value of -1
var value = Math.log2(-1);

console.log(value);

// Output: NaN``````

In the above example, we have used the `log2()` method to compute the base 2 log value of a negative number.

The output `NaN` stands for Not a Number. We get this result because the base 2 log value of negative numbers is undefined.