The Go programming language uses the **`Log2`** function to find the binary logarithm of a float64 number.

To use this function, you must import the `math` package in your file and access the `Log2` function within it using the `.` notation (`math.Log2`). Here, `Log2` is the actual function, while `math` is the Go package that stores the definition of this function.

# Function definition

The definition of the `Log2` function inside the `math` package is as follows:


# Parameters
`Log2` function takes a single argument of type float64.



# Return value

The `Log2` function returns a single value of type int, representing the input argument's binary logarithm.

Following are some of the special return cases:

* **`+Inf`**: Positive infinity is returned if the passed argument is also positive infinity.

* **`-Inf`**: Negative infinity is returned if the passed argument is zero.


* **`NAN`**: The `Log2` function returns `NAN` if the passed argument is either a `NAN` value, negative infinity value, or value which is less than 0.

# Examples

Following is a simple example that generates the binary logarithm value of 5:

package main

import (
	"fmt"
	"math"
)

func main() {
	x := 5.0
	y := math.Log2(x)
	fmt.Print(x, "'s binary logarithm value is ", y)
}

The following example shows how the `Log2` function handles infinite values.

> The `Inf` function returns an infinite value with a sign matching the sign of the argument that it is given.

package main

import (
	"fmt"
	"math"
)

func main() {
	x := math.Inf(-1)
	y := math.Log2(x)
	fmt.Print(x, "'s binary logarithm value is ", y)

	fmt.Print( "\n")


	a := math.Inf(1)
	b := math.Log2(a)
	fmt.Print(a, "'s binary logarithm value is ", b)

}

The following examples show how the `Log2` function handles undefined values.

> We use the `NaN` function to generate the undefined numeric values to test.

package main

import (
	"fmt"
	"math"
)

func main() {
	x := math.NaN()
	y := math.Log2(x)
	fmt.Print(x, "'s binary logarithm value is ", y)
}

What is the Log2 function in golang?

Find the binary logarithm of a float64 in Go using math.Log2. Handle +Inf, -Inf, and NaN values.