Difference between revisions of "Basic lua: Tables"
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| Line 127: | Line 127: | ||
Below are various table functions & advanced methods for interacting with tables. | Below are various table functions & advanced methods for interacting with tables. | ||
| − | === Table | + | === Table Insert === |
| + | ==== Index Tables ==== | ||
| + | <syntaxhighlight lang="lua"> | ||
| + | local t = {"hello ", "world", "world"} | ||
| + | table.insert(t, 3, "goodbye") -- table would now contain hello, world, goodbye, world | ||
| + | </syntaxhighlight> | ||
| + | |||
| + | ==== Keyword Tables ==== | ||
| + | <syntaxhighlight lang="lua"> | ||
| + | local t = {} -- empty table | ||
| + | t["hello"] = "hello world!" -- insert key "hello" along with a value into the t table | ||
| + | </syntaxhighlight> | ||
=== Table Remove === | === Table Remove === | ||
| + | ==== Index Tables ==== | ||
| + | <syntaxhighlight lang="lua"> | ||
| + | local t = {1, 2, 3, 4} | ||
| + | |||
| + | table.remove(t, 3) -- table would now contain 1, 2, 4 | ||
| + | </syntaxhighlight> | ||
| + | ==== Keyword Tables ==== | ||
| + | local t = { | ||
| + | |||
| + | ["hello"] = "hello ", | ||
| + | ["goodbye"] = "goodbye ", | ||
| + | ["world"] = "world" | ||
| + | |||
| + | } | ||
| + | t["goodbye"] = nil -- remove keyword from table by setting it as nil | ||
| + | </syntaxhighlight> | ||
=== Table Concatenation === | === Table Concatenation === | ||
Revision as of 17:21, 3 September 2022
| < | Index | > |
Tables are one of the features of Lua script, that make the scripting language so dynamic & easy to use, as they allow us to easily create tables, insert, remove & sort data. Tables are often comprised of arrays that usually involve keywords - or an index number - & a value. Tables can be accessed using multiple different methods.
Creating Tables
Below I am going to show you how to create various different types of tables/arrays.
Index Tables
| method 1: automatically generated index values | |
|---|---|
local t = {1, 2, 3, 4, 5, "six", 7, "ate", 9} -- automatically assigns an index number to each value starting from 1
local str = "" -- empty string
for i = 1, #t do -- for 1 to table total, print value of index number
str = str .. t[i] -- add current table index value to existing text data in the str variable
if i < #t then str = str .. ", " end -- if i is less than table entry total then insert ", " into the str variable
end
print("table data: " .. str) -- print the table data
print( "table entry total: " .. #(t) ) -- print total of table entries
|
_1.png) |
| method 2: manually created index values | |
|---|---|
local t = {
[1] = 1,
[2] = "two",
[3] = 3,
[4] = 2 * 2,
[5] = "five",
}
local str = "" -- empty string
for i = 1, #t do -- for 1 to table total, print value of index number
str = str .. t[i] -- add current table index value to existing text data in the str variable
if i < #t then str = str .. ", " end -- if i is less than table entry total then insert ", " into the str variable
end
print("table data: " .. str) -- print the table data
print( "table entry total: " .. #(t) ) -- print total of table entries
|
_2.png) |
Keyword Tables
| keywords & values | |
|---|---|
local t = {
["hello world"] = "hello world",
example = "this also works",
camelCaseExample = "this will also work",
snake_case_example = "as will this"
}
for k, v in pairs(t) do
print(k ..": " .. v)
end
print("\n...but as you can see it does not necessarily return them in the order they were created")
|
_3.png) |
Index Values and Sub-Arrays
| auto generated index entries with sub-arrays containing keywords | |
|---|---|
local t = {
{x = 100, y = 300},
{x = 200, y = 111}
}
print("x = " .. t[1].x .. ", y = " .. t[1].y)
|
_4.png) |
Keywords and Sub-Arrays
| keyword tables with keyword sub-arrays containing keywords | |
|---|---|
local t_texts = {
["English"] = {
{txt = "hello world!"},
{txt = "goodbye world!"}
},
["German"] = {
{txt = "hallo welt!"},
{txt = "auf wiedersehen welt"}
}
}
print( t_texts["English"][1].txt )
|
_5.png) |
Advanced Methods and Table Functions
Below are various table functions & advanced methods for interacting with tables.
Table Insert
Index Tables
local t = {"hello ", "world", "world"}
table.insert(t, 3, "goodbye") -- table would now contain hello, world, goodbye, world
Keyword Tables
local t = {} -- empty table
t["hello"] = "hello world!" -- insert key "hello" along with a value into the t table
Table Remove
Index Tables
local t = {1, 2, 3, 4}
table.remove(t, 3) -- table would now contain 1, 2, 4
Keyword Tables
local t = {
["hello"] = "hello ", ["goodbye"] = "goodbye ", ["world"] = "world"
}
t["goodbye"] = nil -- remove keyword from table by setting it as nil </syntaxhighlight>
Table Concatenation
Table Sort
| < | Index | > |
