table.concat()
Part of the Logic & Flow section of Coddy's Lua journey — lesson 5 of 54.
Sometimes you need to combine all the elements in a list-style table into a single string. Lua provides the table.concat() function specifically for this purpose, making it easy to join table elements with a separator of your choice.
The basic syntax looks like this:
local result = table.concat(myTable, separator)Here's a simple example with a list of words:
local words = {"Hello", "from", "Lua"}
local sentence = table.concat(words, " ")
print(sentence) -- Output: Hello from LuaYou can also control which portion of the table to join by providing start and end positions as additional arguments. This is useful when you only want to combine specific elements:
local numbers = {"1", "2", "3", "4", "5"}
local partial = table.concat(numbers, "-", 2, 4)
print(partial) -- Output: 2-3-4The table.concat() function works exclusively with list-style tables and converts each element to a string before joining them.
Challenge
EasyWrite a function buildPath that takes a folders table and a separator string, and returns a single path string with all folders joined by the separator.
Use table.concat() to combine all folder names into a single path string.
Parameters:
folders(table): A list-style table containing folder names as stringsseparator(string): The character or string to use between folder names (e.g.,"/"or"\\")
Returns: A single string with all folders joined by the separator (string)
Cheat sheet
The table.concat() function combines all elements in a list-style table into a single string with a separator:
local result = table.concat(myTable, separator)Basic example:
local words = {"Hello", "from", "Lua"}
local sentence = table.concat(words, " ")
print(sentence) -- Output: Hello from LuaYou can specify start and end positions to join only specific elements:
local numbers = {"1", "2", "3", "4", "5"}
local partial = table.concat(numbers, "-", 2, 4)
print(partial) -- Output: 2-3-4The function works exclusively with list-style tables and converts each element to a string before joining.
Try it yourself
function buildPath(folders, separator)
-- Write code here
end
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Logic & Flow
1Advanced Table Iteration
Iterating with pairs()Iterating with ipairs()pairs() vs. ipairs()Recap - Character Sheet2More Table Library Functions
table.concat()table construction & unpack()table.sort()Custom Sorting with FunctionsRecap - High Score Board