Benchmark for append()

main.go

package main

var size = 1 << 20

func Append() {
	var s []int
	for i := 0; i < size; i++ {
		s = append(s, i)
	}
	_ = s
}

func Make() {
	s := make([]int, size)
	for i := 0; i < size; i++ {
		s[i] = i
	}
	_ = s
}

main_test.go

package main

import "testing"

func BenchmarkAppend(b *testing.B) {
	for n := 0; n < b.N; n++ {
		Append()
	}
}

func BenchmarkMake(b *testing.B) {
	for n := 0; n < b.N; n++ {
		Make()
	}
}