Use parameter type instead of named result parameter

arrays/readme.md

@@ -36,8 +36,8 @@ By running `go test` the compiler will fail with `./sum_test.go:10:15: undefined
 In `sum.go`
 
 ```go
-func Sum(numbers [5]int) (sum int) {
-	return
+func Sum(numbers [5]int) int {
+	return 0
 }
 ```
 
@@ -48,11 +48,12 @@ Your test should now fail with _a clear error message_
 ## Write enough code to make it pass
 
 ```go
-func Sum(numbers [5]int) (sum int) {
+func Sum(numbers [5]int) int {
+	sum := 0
 	for i := 0; i < 5; i++ {
 		sum += numbers[i]
 	}
-	return
+	return sum
 }
 ```
 
@@ -69,11 +70,12 @@ I _wouldn't_ push to master though, because I plan to refactor next. It is nice
 Let's introduce `range` to help clean up our code
 
 ```go
-func Sum(numbers [5]int) (sum int) {
+func Sum(numbers [5]int) int {
+	sum := 0
 	for _, number := range numbers {
 		sum += number
 	}
-	return
+	return sum
 }
 ```
 
@@ -142,11 +144,12 @@ The problem here is we can either
 In our case, no-one else is using our function so rather than having two functions to maintain let's just have one. 
 
 ```go
-func Sum(numbers []int) (sum int) {
+func Sum(numbers []int) int {
+	sum := 0
 	for _, number := range numbers {
 		sum += number
 	}
-	return
+	return sum
 }
 ```
 
@@ -294,15 +297,15 @@ Change the test back again and run it, you should have test output looking like
 What we need to do is iterate over the varargs, calculate the sum using our `Sum` function from before and then add it to the slice we will return
 
 ```go
-func SumAll(numbersToSum ...[]int) (sums []int) {
+func SumAll(numbersToSum ...[]int) []int {
 	lengthOfNumbers := len(numbersToSum)
-	sums = make([]int, lengthOfNumbers)
+	sums := make([]int, lengthOfNumbers)
 
 	for i, numbers := range numbersToSum {
 		sums[i] = Sum(numbers)
 	}
 
-	return
+	return sums
 }
 ```
 
@@ -321,12 +324,13 @@ As mentioned, slices have a capacity. If you have a slice with a capacity of 2 a
 However you can use the `append` function which takes a slice and a new value, returning a new slice with all the items in it.
 
 ```go
-func SumAll(numbersToSum ...[]int) (sums []int) {
+func SumAll(numbersToSum ...[]int) []int {
+	var sums []int
 	for _, numbers := range numbersToSum {
 		sums = append(sums, Sum(numbers))
 	}
 
-	return
+	return sums
 }
 ```
 
@@ -360,13 +364,14 @@ Rename the function to `SumAllTails` and re-run the test
 ## Write enough code to make it pass
 
 ```go
-func SumAllTails(numbersToSum ...[]int) (sums []int) {
+func SumAllTails(numbersToSum ...[]int) []int {
+	var sums []int
 	for _, numbers := range numbersToSum {
 		tail := numbers[1:]
 		sums = append(sums, Sum(tail))
 	}
 
-	return
+	return sums
 }
 ```
 
@@ -416,7 +421,8 @@ Oh no! It's important to note the test _has compiled_, it is a runtime error. Co
 ## Write enough code to make it pass
 
 ```go
-func SumAllTails(numbersToSum ...[]int) (sums []int) {
+func SumAllTails(numbersToSum ...[]int) []int {
+	var sums []int
 	for _, numbers := range numbersToSum {
 		if len(numbers) == 0 {
 			sums = append(sums, 0)
@@ -426,7 +432,7 @@ func SumAllTails(numbersToSum ...[]int) (sums []int) {
 		}
 	}
 
-	return
+	return sums
 }
 ```
 

arrays/v1/sum.go

@@ -1,8 +1,9 @@
 package main
 
-func Sum(numbers [5]int) (sum int) {
+func Sum(numbers [5]int) int {
+	sum := 0
 	for i := 0; i < 5; i++ {
 		sum += numbers[i]
 	}
-	return
+	return sum
 }

arrays/v2/sum.go

@@ -1,8 +1,9 @@
 package main
 
-func Sum(numbers [5]int) (sum int) {
+func Sum(numbers [5]int) int {
+	sum := 0
 	for _, number := range numbers {
 		sum += number
 	}
-	return
+	return sum
 }

arrays/v3/sum.go

@@ -1,8 +1,9 @@
 package main
 
-func Sum(numbers []int) (sum int) {
+func Sum(numbers []int) int {
+	sum := 0
 	for _, number := range numbers {
 		sum += number
 	}
-	return
+	return sum
 }

arrays/v4/sum.go

@@ -1,19 +1,21 @@
 package main
 
-func Sum(numbers []int) (sum int) {
+func Sum(numbers []int) int {
+	sum := 0
 	for _, number := range numbers {
 		sum += number
 	}
-	return
+	return sum
 }
 
-func SumAll(numbersToSum ...[]int) (sums []int) {
+
+func SumAll(numbersToSum ...[]int) []int {
 	lengthOfNumbers := len(numbersToSum)
-	sums = make([]int, lengthOfNumbers)
+	sums := make([]int, lengthOfNumbers)
 
 	for i, numbers := range numbersToSum {
 		sums[i] = Sum(numbers)
 	}
 
-	return
+	return sums
 }

arrays/v5/sum.go

@@ -1,16 +1,18 @@
 package main
 
-func Sum(numbers []int) (sum int) {
+func Sum(numbers []int) int {
+	sum := 0
 	for _, number := range numbers {
 		sum += number
 	}
-	return
+	return sum
 }
 
-func SumAll(numbersToSum ...[]int) (sums []int) {
+func SumAll(numbersToSum ...[]int) []int {
+	var sums []int
 	for _, numbers := range numbersToSum {
 		sums = append(sums, Sum(numbers))
 	}
 
-	return
+	return sums
 }

arrays/v6/sum.go

@@ -1,17 +1,19 @@
 package main
 
-func Sum(numbers []int) (sum int) {
+func Sum(numbers []int) int {
+	sum := 0
 	for _, number := range numbers {
 		sum += number
 	}
-	return
+	return sum
 }
 
-func SumAllTails(numbersToSum ...[]int) (sums []int) {
+func SumAllTails(numbersToSum ...[]int) []int {
+	var sums []int
 	for _, numbers := range numbersToSum {
 		tail := numbers[1:]
 		sums = append(sums, Sum(tail))
 	}
 
-	return
+	return sums
 }

arrays/v7/sum.go

@@ -1,13 +1,16 @@
 package main
 
-func Sum(numbers []int) (sum int) {
+func Sum(numbers []int) int {
+	sum := 0
 	for _, number := range numbers {
 		sum += number
 	}
-	return
+	return sum
 }
 
-func SumAllTails(numbersToSum ...[]int) (sums []int) {
+
+func SumAllTails(numbersToSum ...[]int) []int {
+	var sums []int
 	for _, numbers := range numbersToSum {
 		if len(numbers) == 0 {
 			sums = append(sums, 0)
@@ -17,5 +20,5 @@ func SumAllTails(numbersToSum ...[]int) (sums []int) {
 		}
 	}
 
-	return
+	return sums
 }

for/readme.md

@@ -36,7 +36,7 @@ All you need to do right now is enough to make it compile so you can check your
 ```go
 package main
 
-func Repeat(character string) (repeated string)  {
+func Repeat(character string) string  {
 	return
 }
 ```
@@ -50,11 +50,12 @@ Isn't it nice to know you already know enough Go to write tests for some basic p
 The `for` syntax is very unremarkable and follows most C-like languages.
 
 ```go
-func Repeat(character string) (repeated string) {
+func Repeat(character string) string {
+	var repeated string
 	for i := 0; i < 5; i++ {
 		repeated = repeated + character
 	}
-	return
+	return repeated
 }
 ```
 
@@ -67,11 +68,12 @@ Now it's time to refactor and introduce another construct `+=`
 ```go
 const repeatCount = 5
 
-func Repeat(character string) (repeated string) {
+func Repeat(character string) string {
+	var repeated string
 	for i := 0; i < repeatCount; i++ {
 		repeated += character
 	}
-	return
+	return repeated
 }
 ```
 

for/v1/repeat.go

@@ -1,8 +1,9 @@
 package main
 
-func Repeat(character string) (repeated string) {
+func Repeat(character string) string {
+	var repeated string
 	for i := 0; i < 5; i++ {
 		repeated = repeated + character
 	}
-	return
+	return repeated
 }

for/v2/repeat.go

@@ -2,9 +2,10 @@ package main
 
 const repeatCount = 5
 
-func Repeat(character string) (repeated string) {
+func Repeat(character string) string {
+	var repeated string
 	for i := 0; i < repeatCount; i++ {
 		repeated += character
 	}
-	return
+	return repeated
 }

for/vx/repeat.go

@@ -2,9 +2,10 @@ package main
 
 const repeatCount = 5
 
-func Repeat(character string) (repeated string) {
+func Repeat(character string) string {
+	var repeated string
 	for i := 0; i < repeatCount; i++ {
 		repeated += character
 	}
-	return
+	return repeated
 }

integers/readme.md

@@ -34,7 +34,7 @@ Inspect the compilation error
 Write enough code to satisfy the compiler *and that's all* - remember we want to check that our tests fail for the correct reason.
 
 ```go
-func Add(x, y int) (sum int) {
+func Add(x, y int) int {
 	return
 }
 ```
@@ -45,12 +45,16 @@ Now run the tests and we should be happy that the test is correctly reporting wh
 
 `adder_test.go:10: expected '4' but got '0'`
 
+If you have noticed we learnt about _named return value_ in the [last](/hello-world/readme.md#one...last...refactor?) section but aren't using the same here.
+It should generally be used when the meaning of the result isn't clear from context, in our case it's pretty much clear that `Add` function will add the parameters.
+You can refer [this](https://github.com/golang/go/wiki/CodeReviewComments#named-result-parameters) wiki for more details.
+
 ## Write enough code to make it pass
 
 In the strictest sense of TDD we should now write the _minimal amount of code to make the test pass_. A pedantic programmer may do this
 
 ```go
-func Add(x, y int) (sum int) {
+func Add(x, y int) int {
 	return 4
 }
 ```
@@ -64,7 +68,7 @@ Once we're more familiar with Go's syntax I will introduce a technique called Pr
 For now, let's fix it properly
 
 ```go
-func Add(x, y int) (sum int) {
+func Add(x, y int) int {
 	return x + y
 }
 ```
@@ -83,7 +87,7 @@ You can add documentation to functions with comments, and these will appear in G
 
 ```go
 // Add takes two integers and returns the sum of them
-func Add(x, y int) (sum int) {
+func Add(x, y int) int {
 	return x + y
 }
 ```
@@ -115,4 +119,4 @@ What we have covered:
 - More practice of the TDD workflow
 - Integers, addition
 - Writing better documentation so users of our code can understand its usage quickly
-- Examples of how to use our code, which are checked as part of our tests
+- Examples of how to use our code, which are checked as part of our tests

integers/v1/adder.go

@@ -1,5 +1,5 @@
 package main
 
-func Add(x, y int) (sum int) {
+func Add(x, y int) int {
 	return x + y
 }