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Co-authored-by: June <[email protected]>

Author: andrerfcsantos

concepts/pointers/about.md

@@ -31,18 +31,18 @@ The piece of memory that is associated with `a` will now will now be storing the
 
 ## Pointers
 
-While variables allow us to refer to values in memory, sometimes it's useful to know the **memory address** to which the variable is pointing. **Pointers** hold the memory addresses of those values. A pointer declaration looks like this:
+While variables allow us to refer to values in memory, sometimes it's useful to know the **memory address** to which the variable is pointing. **Pointers** hold the memory addresses of those values. You declare a variable with a pointer type by prefixing the underlying type with an asterisk: 
 
 ```go
 var p *int // 'p' contains the memory address of an integer
 ```
 
-Here we declaring a variable `p` of type `*int`. The type `*int` means "pointer to int". In other words, we are saying that `p` is a pointer to int, which means that `p` will hold the memory address of an integer. The zero value of pointers is `nil` because a `nil` pointer holds no memory address.
+Here we declaring a variable `p` of type "pointer to int" (`*int`). This means that `p` will hold the memory address of an integer. The zero value of pointers is `nil` because a `nil` pointer holds no memory address.
 
 ### Getting a pointer to a variable
 
 To find the memory address of the value of a variable, we can use the `&` operator. 
-For example, if we want to find and store the member address of variable `a` in the pointer `p`, we can do the following:
+For example, if we want to find and store the memory address of variable `a` in the pointer `p`, we can do the following:
 
 ```go
 var a int
@@ -54,7 +54,7 @@ p = &a // the variable 'p' will hold the memory address of 'a'
 
 ### Accessing the value via a pointer (dereferencing)
 
-When we have a pointer, we might want to know the value stored in the memory address to which it points. We can do this using the `*` operator:
+When we have a pointer, we might want to know the value stored in the memory address the pointer represents. We can do this using the `*` operator:
 
 ```go
 var a int 
@@ -87,6 +87,11 @@ Assigning to `*pa` will change the value stored at the memory address `pa` holds
 
 A note of caution however: always check if a pointer is not `nil` before dereferencing. Dereferencing a `nil` pointer will make the program crash at runtime!
 
+```go
+var p *int // p is nil initially
+fmt.Println(*p)
+// panic: runtime error: invalid memory address or nil pointer dereference
+
 ### Pointers to structs
 
 So far we've only seen pointers to primitive values. We can also create pointers for structs:
@@ -143,9 +148,10 @@ fmt.Println(ages)
 // The changes the function 'addPeterAge' made to the map are visible after the function ends!
 ```
 
+The same applies when changing an existing item in a slice. However, actions that return a new slice like `append` will **not** modify the slice outside of the function.
 ## Pointer arithmetic
 
-Unlike other languages, pointer arithmetic is not allowed in Go. This means that snippets like the following are invalid:
+Unlike other languages, Go does not support pointer arithmetic. This means you cannot go from a memory address of one value to the address of another by incrementing the pointer value. So snippets like the following are invalid:
 
 ```go
 a := 2

concepts/pointers/introduction.md

@@ -1,4 +1,4 @@
-# About
+# Introduction
 
 Like many other languages, Go has pointers. 
 If you're new to pointers, they can feel a little mysterious but once you get used to them, they're quite straight-forward.

exercises/concept/election-day/.docs/instructions.md

@@ -6,6 +6,7 @@ elections are run to elect a new president.
 
 In this year's election, it was decided that a new digital system to
 count the votes was needed. The school needs your help building this new system.
+
 ## 1. Create a vote counter
 
 One of the first things that the new voting system needs is a vote counter.

exercises/concept/election-day/.meta/design.md

@@ -15,6 +15,7 @@ The goal of this exercise is to teach the basics of pointers and how they work i
 ## Out of scope
 
 - Unsafe pointers
+- Pointer receivers for methods (this is parts of the `methods` concept)
 
 ## Concepts