Update 20221104.7 ⭐️ How to iterate over tables in Lua.md

sources/tech/20221104.7 ⭐️ How to iterate over tables in Lua.md

@@ -19,30 +19,28 @@ In the [Lua][1] programming language, an array is called a table. A table is use
 To create a table in Lua, you instantiate the table with an arbitrary name:
 
 ```
-mytable ={}
+mytable = {}
 ```
 
 There are different ways you can structure your data in a table. You could fill it with values, essentially creating a list (called a list in some languages):
 
 ```
-mytable ={'zombie','apocalypse'}
+mytable = {'zombie','apocalypse'}
 ```
 
 Or you could create an associated array (called a map or dictionary in some languages). You can add arbitrary keys to the table using dot notation. You can also add a value to that key the same way you add a value to a variable:
 
 ```
-myarray ={}
-
-myarray.baz='happy'
-
-myarray.qux='halloween'
+myarray = {}
+myarray.baz = 'happy'
+myarray.qux = 'halloween'
 ```
 
 You can add verification with the `assert()` function:
 
 ```
-[assert][2](myarray.baz=='happy','unexpected value in myarray.baz')
-[assert][2](myarray.qux=='halloween','unexpected value in myarray.qux')
+[assert][2](myarray.baz == 'happy', 'unexpected value in myarray.baz')
+[assert][2](myarray.qux == 'halloween', 'unexpected value in myarray.qux')
 ```
 
 You now have two tables: a list-style `mytable` and an associative array-style `myarray`.
@@ -53,10 +51,8 @@ Lua's `pairs()` function extracts key and value pairs from a table.
 
 ```
 print('pairs of myarray:')
-for k,v in pairs(myarray)do
-
-  print(k,v)
-
+for k, v in pairs(myarray) do
+  print(k, v)
 end
 ```
 
@@ -64,9 +60,7 @@ Here's the output:
 
 ```
 pairs of myarray:
-
 baz     happy
-
 qux     halloween
 ```
 
@@ -74,10 +68,8 @@ If there are no keys in a table, Lua uses an index. For instance, the `mytable`
 
 ```
 print('pairs of mytable:')
-for k,v in pairs(mytable)do
-
-  print(k,v)
-
+for k, v in pairs(mytable) do
+  print(k, v)
 end
 ```
 
@@ -94,10 +86,8 @@ To account for the fact that tables without keys are common, Lua also provides t
 
 ```
 print('ipairs of mytable:')
-for i,v in ipairs(mytable)do
-
-  print(i,v)
-
+for i, v in ipairs(mytable) do
+  print(i, v)
 end
 ```
 
@@ -111,13 +101,10 @@ The output is, in this case, the same as the output of `pairs`:
 However, watch what happens when you add a key and value pair to `mytable`:
 
 ```
-mytable.surprise='this value has a key'
-
+mytable.surprise = 'this value has a key'
 print('ipairs of mytable:')
-for i,v in ipairs(mytable)do
-
-  print(i,v)
-
+for i, v in ipairs(mytable) do
+  print(i, v)
 end
 ```
 
@@ -132,10 +119,8 @@ The key and value pair, however, have been stored in the table:
 
 ```
 print('pairs of mytable:')
-for k,v in ipairs(mytable)do
-
-  print(k,v)
-
+for k, v in ipairs(mytable) do
+  print(k, v)
 end
 ```
 
@@ -144,7 +129,6 @@ The output:
 ```
 1          zombie
 2          apocalypse
-
 surprise   this value has a key
 ```
 
@@ -154,21 +138,13 @@ You don't have to iterate over a table to get data out of it. You can call arbit
 
 ```
 print('call by index:')
-
 print(mytable[2])
-
 print(mytable[1])
-
 print(myarray[2])
-
 print(myarray[1])
-
 print('call by key:')
-
 print(myarray['qux'])
-
 print(myarray['baz'])
-
 print(mytable['surprise'])
 ```
 
@@ -176,21 +152,14 @@ The output:
 
 ```
 call by index:
-
 apocalypse
-
 zombie
-
 nil
-
 nil
 
 call by key:
-
 halloween
-
 happy
-
 this value has a key
 ```