Initial array slices

learn_go_with_tests/arrays/go.mod

@@ -0,0 +1,3 @@
+module myarray
+
+go 1.21.0

learn_go_with_tests/arrays/sum.go

@@ -0,0 +1,23 @@
+package arrays
+
+func Sum(a []int) int {
+	sum := 0
+
+	//aternatively
+	// for i := 0; i < 5; i++ {
+	// 	sum += a[i]
+	// }
+
+	// OR
+
+	// for i := range a {
+	// 	sum += a[i]
+	// }
+
+	// OR
+
+	for _, v := range a {
+		sum += v
+	}
+	return sum
+}

learn_go_with_tests/arrays/sum_test.go

@@ -0,0 +1,38 @@
+package arrays
+
+import "testing"
+
+// go test -cover will show the test coverage for our package.
+
+func TestSum(t *testing.T) {
+
+	t.Run("sum collection of 5 of integers", func(t *testing.T) {
+		numbers := []int{1, 2, 3, 4, 5}
+
+		got := Sum(numbers)
+		expected := 15
+
+		// https://pkg.go.dev/fmt
+		if got != expected {
+			t.Errorf("got %d expected %d given, %v", got, expected, numbers)
+		}
+	})
+
+	// go test -cover will show the test coverage for our package.
+
+	// You can see that commenting out this "duplicate" function still retains 100%
+	// test coverage, which is how we know it's redundant.
+
+	// t.Run("sum a collection of any size", func(t *testing.T) {
+	// 	numbers := []int{1, 2, 3}
+
+	// 	got := Sum(numbers)
+	// 	expected := 6
+
+	// 	// https://pkg.go.dev/fmt
+	// 	if got != expected {
+	// 		t.Errorf("got %d expected %d given, %v", got, expected, numbers)
+	// 	}
+	// })
+
+}