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timetimerbenchmarkinggo

How do you time a function in Go and return its runtime in milliseconds?

How do you time a function in Go and return its runtime in milliseconds?

Solution

  • Use the Go testing package to benchmark the function. For example,

    package main

import (
    "fmt"
    "testing"
)

// the function to be benchmarked
func Function(n int) int64 {
    n64 := int64(n)
    return n64 * n64
}

func BenchmarkFunction(b *testing.B) {
    n := 42
    for i := 0; i < b.N; i++ {
        _ = Function(n)
    }
}

func main() {
    br := testing.Benchmark(BenchmarkFunction)
    fmt.Println(br)
}

    Output:

    500000000            4.22 ns/op

    You can also use the Go gotest command to run benchmarks.