math.Round() Function in Golang With Examples

Go language provides inbuilt support for basic constants and mathematical functions to perform operations on the numbers with the help of the math package. You can round off the given number to the nearest integer(rounding half away from zero) with the help of Round() function provided by the math package. So, you need to add a math package in your program with the help of the import keyword to access the Round() function.

Syntax:

func Round(a float64) float64

• If you pass -Inf or +Inf in this function like Round(-Inf) or Round(+Inf), then this function will return -Inf or +Inf.
• If you pass -0 or +0 in this function like Round(-0) or Round(+0), then this function will return -0 or +0.
• If you pass NaN in this function like Round(NaN), then this function will return NaN.

Example 1:

// Golang program to illustrate how to
// round off the given number to the
// nearest integer

package main

import (
    "fmt"
    "math"
)

// Main function
func main() {

    // Finding the nearest integer
    // of the given numbers
    // Using Round() function
    res_1 := math.Round(36.98)
    res_2 := math.Round(-100.98)
    res_3 := math.Round(math.Inf(-1))
    res_4 := math.Round(math.NaN())
    res_5 := math.Round(math.Inf(1))

    // Displaying the result
    fmt.Printf("Result 1: %.1f", res_1)
    fmt.Printf("\nResult 2: %.1f", res_2)
    fmt.Printf("\nResult 3: %.1f", res_3)
    fmt.Printf("\nResult 4: %.1f", res_4)
    fmt.Printf("\nResult 5: %.1f", res_5)

}

Output:

Result 1: 37.0
Result 2: -101.0
Result 3: -Inf
Result 4: NaN
Result 5: +Inf

Example 2:

// Golang program to illustrate how to
// round off the given number to the
// nearest integer

package main

import (
    "fmt"
    "math"
)

// Main function
func main() {

    // Finding the nearest integer
    // of the given numbers
    // Using Round() function
    nvalue_1 := math.Round(49.89)
    nvalue_2 := math.Round(-4.567)

    // Finding sum of the given numbers
    res := nvalue_1 + nvalue_2
    fmt.Printf("%.2f + %.2f = %.2f",
           nvalue_1, nvalue_2, res)

}

Output:

50.00 + -5.00 = 45.00