# JavaScript | Math.log2() function

The Math.log10() is an inbuilt function in JavaScript which give the value of base 2 logarithms of any number.
Syntax:

`Math.log2(p)`

Parameters:

• Here the parameter p is any number whose base 2 logarithms is to be calculated.
• Return Values:

• It returns the value of base 2 logarithms of any number.

Examples:

```Input:
Math.log2(5)
Output:
2.321928094887362
```

Explanation:
Here value of bese 2 logarithms of number 5 is 2.321928094887362 as shown output.

```Input:
Math.log2(10)
Output:
3.321928094887362
```

Let’s see some JavaScript code on this function:
Code #1:

 `// Different numbers are being taken ` `// as the parameter of the function. ` `console.log(Math.log2(1000)); ` `console.log(Math.log2(12)); ` `console.log(Math.log2(26)); ` `console.log(Math.log2(5)); `

/div>

Output:

```> 9.965784284662087
> 3.584962500721156
> 4.700439718141092
> 2.321928094887362```

Code #2:

 `// Taken parameter from 1 to 19 incremented by 3. ` `for` `(i = 1; i < 20; i += 3) { ` `    ``console.log(Math.log2(i)); ` `} `

Output:

```> 0
> 2
> 2.807354922057604
> 3.321928094887362
> 3.700439718141092
> 4
> 4.247927513443585
```

Errors and exceptions:

1. Parameters for this function should always be a number otherwise it return NaN i.e, not a number when its parameter taken as string.
 `// Parameters for this function should always be a ` `// number otherwise it return NaN i.e, not a number ` `// when its parameter taken as string. ` `console.log(Math.log2(``"gfg"``)); `

Output:

```> NaN
```
2. This function gives error when its parameter taken as complex number because it accept only integer value as the parameter.
 `// Parametes can never be a complex number because ` `// it accept only integer value as the parameter. ` `console.log(Math.log2(1 + 2i)); `

Output:

```Error: Invalid or unexpected token
```
Application:

• Whenever we need the value of base 2 logarithms of any number that time we take the help of this function.Its value needed many times in mathematics problem.
Let’s see JavaScript code for this application:
Code #1:

 `// taking parameter as number 14 and calculated in the form of function. ` `function` `value_of_base_2_logarithms_of_any_number() ` `{ ` `    ``return` `Math.log2(14); ` `} ` `console.log(value_of_base_2_logarithms_of_any_number()); `

Output:

`> 3.807354922057604`