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Golang math.Nextafter() Function with Examples

Golang | math.Nextafter() Function: Here, we are going to learn about the Nextafter() function of the math package with its usages, syntax, and examples.
Submitted by IncludeHelp, on September 02, 2021

math.Nextafter()

The Nextafter() function is an inbuilt function of the math package which is used to get the next representable float64 (floating-point) value after the first parameter (x) towards the second parameter (y).

It accepts two parameters (x, y) and returns the next representable float64 value after x towards y.

Syntax

func Nextafter(x, y float64) (r float64)

Parameters

• x, y : The values to be used to find the next representable float64 value after x towards y.

Return Value

The return type of Nextafter() function is a float64, it returns the next representable float64 value after x towards y.

Special Cases

• Nextafter(x, x) = x
  If both the parameters are same, the function returns the same value.
• Nextafter(NaN, y) = NaN
  If the first parameter is NaN, the function returns NaN.
• Nextafter(x, NaN) = NaN
  If the second parameter is NaN, the function returns NaN.

Example 1

// Golang program to demonstrate the
// example of math.Nextafter() Function

package main

import (
	"fmt"
	"math"
)

func main() {
	fmt.Println(math.Nextafter(1.0, 2.0))
	fmt.Println(math.Nextafter(1.0, 1.5))
	fmt.Println(math.Nextafter(-10.23, -20))
	fmt.Println(math.Nextafter(10, 5))
	fmt.Println(math.Nextafter(1.49, -2))

	fmt.Println(math.Nextafter(1.23, 1.23))
	fmt.Println(math.Nextafter(1.23, math.NaN()))
	fmt.Println(math.Nextafter(math.NaN(), 1.23))
}

Output:

1.0000000000000002
1.0000000000000002
-10.230000000000002
9.999999999999998
1.4899999999999998
1.23
NaN
NaN

Example 2

// Golang program to demonstrate the
// example of math.Nextafter() Function

package main

import (
	"fmt"
	"math"
)

func main() {
	var x float64
	var y float64
	var NextafterXY float64

	x = 1.23
	y = 1.23
	NextafterXY = math.Nextafter(x, y)
	fmt.Println("Next representable float64 value after", x, "towards", y, "is", NextafterXY)

	x = -1.23
	y = 1.23
	NextafterXY = math.Nextafter(x, y)
	fmt.Println("Next representable float64 value after", x, "towards", y, "is", NextafterXY)

	x = 0.5
	y = 1
	NextafterXY = math.Nextafter(x, y)
	fmt.Println("Next representable float64 value after", x, "towards", y, "is", NextafterXY)

	x = math.NaN()
	y = 1.23
	NextafterXY = math.Nextafter(x, y)
	fmt.Println("Next representable float64 value after", x, "towards", y, "is", NextafterXY)

	x = 1.23
	y = math.NaN()
	NextafterXY = math.Nextafter(x, y)
	fmt.Println("Next representable float64 value after", x, "towards", y, "is", NextafterXY)
}

Output:

Next representable float64 value after 1.23 towards 1.23 is 1.23
Next representable float64 value after -1.23 towards 1.23 is -1.2299999999999998
Next representable float64 value after 0.5 towards 1 is 0.5000000000000001
Next representable float64 value after NaN towards 1.23 is NaN
Next representable float64 value after 1.23 towards NaN is NaN

Golang math Package Constants and Functions »

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