Primes in Golang

primes.go

package main

import (
	"fmt"
	"math"
)

func main() {
	sum := summation(2000000)
	fmt.Println(sum)
}

func primes(limit int) []int {
	primes := []int{}
	for i := 0; i <= limit; i++ {
		if isPrime(i) {
			primes = append(primes, i)
		}
	}
	return primes
}

func summation(limit int) int {
	primes := primes(limit)
	sum := 0
	for i := 0; i < len(primes); i++ {
		sum += primes[i]
	}

	return sum
}

func isPrime(n int) bool {
	if n < 2 {
		return false
	}
	max := int(math.Sqrt(float64(n)))
	for i := 2; i <= max; i++ {
		if n%i == 0 {
			return false
		}
	}
	return true
}

primes_test.go

package main

import (
	"fmt"
	"testing"
)

func BenchmarkSummation(b *testing.B) {
	fmt.Println("Benchmark Limit 2000000")
	summation(2000000)
}

# in terminal run $ go test -bench=.