Better merge array by key example, fixed spelling mistakes

operators/equals.md

@@ -108,7 +108,7 @@ will output
 a: frog
 ```
 
-## Two non existant keys are equal
+## Two non existent keys are equal
 Given a sample.yml file of:
 ```yaml
 a: frog

operators/multiply-merge.md

@@ -234,10 +234,12 @@ will output
 ```
 
 ## Merge arrays of objects together, matching on a key
-It's a complex command, the trickyness comes from needing to have the right context in the expressions.
-First we save the second array into a variable '$two' which lets us reference it later.
-We then need to update the first array. We will use the relative update (|=) because we need to update relative to the current element of the array in the LHS in the RHS expression. 
-We set the current element of the first array as $cur. Now we multiply (merge) $cur with the matching entry in $two, by passing $two through a select filter.
+There are two parts of the complex expression. The first part is doing the hard work, it creates a map from the arrays keyed by '.a', 
+so that there are no duplicates. The second half converts that map back to an array.
+
+To use this, you will need to update '.[]' to be the expression to your array (e.g. .my.array[]), and '.a' to be the key field of your array (e.g. '.name')
+
+Thanks Kev from [stackoverflow](https://stackoverflow.com/a/70109529/1168223)
 
 
 Given a sample.yml file of:
@@ -260,7 +262,9 @@ And another sample another.yml file of:
 ```
 then
 ```bash
-yq eval-all '(select(fi==1) | .[]) as $two | select(fi==0) | .[] |= (. as $cur |  $cur * ($two | select(.a == $cur.a)))' sample.yml another.yml
+yq eval-all '((.[] | {.a: .}) as $item ireduce ({}; . * $item )) as $uniqueMap
+| ( $uniqueMap  | to_entries | .[]) as $item ireduce([]; . + $item.value)
+' sample.yml another.yml
 ```
 will output
 ```yaml
@@ -271,6 +275,8 @@ will output
 - a: banana
   b: bananaB
   c: bananaC
+- a: dingo
+  c: dingoC
 ```
 
 ## Merge to prefix an element

operators/string-operators.md

@@ -209,7 +209,7 @@ will output
 ```
 
 ## Test using regex
-Like jq'q equivalant, this works like match but only returns true/false instead of full match details
+Like jq'q equivalent, this works like match but only returns true/false instead of full match details
 
 Given a sample.yml file of:
 ```yaml