Some benchmarking just for fine

main_test.go

package main

import "testing"

/**
go test -v -bench=.
goos: linux
goarch: amd64
pkg: github.com/ggirtsou/benchmark
BenchmarkSliceLookup-8   	  200000	      6651 ns/op
BenchmarkMapLookup-8     	200000000	         7.08 ns/op
PASS
ok  	github.com/ggirtsou/benchmark	4.774s
*/

// omg please don't do this in production
func BenchmarkSliceLookup(b *testing.B) {
	var data []int
	for i := 0; i < 1000000; i++ {
		data = append(data, i)
	}

	for n := 0; n < b.N; n++ {
		for _, v := range data {
			if v == 12345 {
				break
			}
		}
	}
}

func BenchmarkMapLookup(b *testing.B) {
	var s struct{}
	data := make(map[int]struct{})
	for i := 0; i < 1000000; i++ {
		data[i] = s
	}

	for n := 0; n < b.N; n++ {
		_ = data[12345]
	}
}