small changes to basics

Author: travissarles

tutorials/tour/_posts/2017-02-13-basics.md

@@ -26,7 +26,9 @@ This is an easy, zero-setup way to experiment with pieces of Scala code.
 ## Expressions
 
 Expressions are computable statements.
-
+```
+1 + 1
+```
 You can output results of expressions using `println`.
 
 ```tut
@@ -61,6 +63,8 @@ Types of values can be inferred, but you can also explicitly state the type, lik
 val x: Int = 1 + 1
 ```
 
+Notice how the type declaration `Int` comes after the identifier `x`. You also need a `:`.  
+
 ### Variables
 
 Variables are like values, except you can re-assign them. You can define a variable with the `var` keyword.
@@ -77,7 +81,8 @@ As with values, you can explicitly state the type if you want:
 var x: Int = 1 + 1
 ```
 
-### Blocks
+
+## Blocks
 
 You can combine expressions by surrounding them with `{}`. We call this a block.
 
@@ -94,7 +99,7 @@ println({
 
 Functions are expressions that take parameters.
 
-You can define a function that returns a given integer plus one:
+You can define an anonymous function (i.e. no name) that returns a given integer plus one:
 
 ```tut
 (x: Int) => x + 1
@@ -136,7 +141,7 @@ def add(x: Int, y: Int): Int = x + y
 println(add(1, 2)) // 3
 ```
 
-Methods cannot be named with the `val` or `var` keywords.
+Notice how the return type is declared _after_ the parameter list: `: Int`. Methods cannot be named with the `val` or `var` keywords.
 
 ```tut:nofail
 def add(x: Int, y: Int): Int = x + y
@@ -160,6 +165,16 @@ println("Hello, " + name + "!")
 
 There are some other differences, but for now, you can think of them as something similar to functions.
 
+Method can have multi-line expressions as well.
+```tut
+def getSquareString(input: Double): String = {
+  val square = input * input
+  square.toString
+}
+```
+You can use the `return` but it is not necessary or idiomatic. Expressions
+
+
 ## Classes
 
 You can define classes with the `class` keyword followed by its name and constructor parameters.
@@ -170,6 +185,7 @@ class Greeter(prefix: String, suffix: String) {
     println(prefix + name + suffix)
 }
 ```
+The return type of the method `greet` is `Unit` which says there's nothing meaningful to return. It's used similarly to `void` in Java and C but the main difference is that there is actually a singleton value of type `Unit`, written `()`. 
 
 You can make an instance of a class with the `new` keyword.