Add channels example.

channels.go

@@ -0,0 +1,48 @@
+package workshop
+
+import "fmt"
+
+func average(numbers []float64, c chan float64) {
+	c <- sum(numbers) / float64(len(numbers))
+}
+
+func sum(numbers []float64) float64 {
+	var sum = 0.0
+	for i := 0; i < len(numbers); i++ {
+		sum += numbers[i]
+	}
+	return float64(sum)
+}
+
+func bufferedSum(numbers []float64, c chan float64) {
+	var sum float64
+	for i := 0; i < len(numbers); i++ {
+		sum += numbers[i]
+	}
+	c <- sum
+}
+
+func channels() {
+	var numbers = []float64{
+		1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
+	}
+	c := make(chan float64)
+	go average(numbers, c)
+
+	avg := <-c
+
+	assert(avg == 5.5)
+
+	c1 := make(chan float64, 10)
+
+	numbers2 := []float64{
+		1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
+	}
+
+	defer func() {
+		go bufferedSum(numbers2, c1)
+	}()
+
+	bufferSum := <-c1
+	fmt.Println(bufferSum)
+}

practice/closures_test.go

@@ -2,6 +2,8 @@ package practice
 
 import (
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestAverage(t *testing.T) {
@@ -14,7 +16,7 @@ func TestAverage(t *testing.T) {
 	}
 }
 
-func TestStandarDeviation(t *testing.T) {
+func TestStandardDeviation(t *testing.T) {
 	numbers := []float64{
 		5.3,
 		2.5,
@@ -29,3 +31,17 @@ func TestStandarDeviation(t *testing.T) {
 		t.Error("Expected 2.49 but received ", actual)
 	}
 }
+
+func TestStandardDeviation2(t *testing.T) {
+	numbers := []float64{
+		5.3,
+		2.5,
+		3.75,
+		9.55,
+		8.5,
+		6.75,
+	}
+	actual := standardDeviation(numbers)()
+	expected := "2.49"
+	assert.Equal(t, actual, expected)
+}