Learn LUA, The Basics | Episode 1

Summary

This episode of 'Learning Lua' introduces the basics of the Lua programming language, covering its history, usage in various applications like game development, and how to write simple scripts. Topics include printing messages, variables, functions, math equations, text inputs, and if statements. The tutorial concludes with a challenge to create a sales tax calculator.

Takeaways

• 📜 Lua was created in 1993 and is versatile, used in applications like Roblox, 5M Love, and more.
• 💻 Lua can be edited in various programs, including Roblox Studio, Visual Studio Code, Atom, and any text editor.
• 📝 Comments in Lua are made using `--` for single lines or `--[[]]` for multi-line comments.
• 🖨 The `print` function in Lua is used to output text or variables to the console, enclosed in quotation marks.
• 🔑 Variables in Lua are declared with `local` to limit their scope to the script, followed by the variable name and assignment.
• 📚 Lua functions are defined using `local function functionName() end` and can be executed multiple times as needed.
• 🔢 Basic math operations in Lua include addition, subtraction, multiplication, division, and exponentiation, stored in variables or printed directly.
• 📉 Lua supports different ways to perform and print math equations, with variables for reusability and direct print for simplicity.
• 📑 Text input in Lua is handled through the command prompt, using `io.read()` to capture user input and store it in a variable.
• 🔄 Lua's `if` statements allow conditional execution of code based on comparisons like equality (`==`), inequality (`~=`), less than (`<`), and greater than (`>`).
• 🛒 The tutorial concludes with a challenge to create a sales tax calculator, demonstrating Lua's practical application in simple calculations.

Q & A

What is the history of the Lua programming language?

Lua was born in 1993 and has been used in various applications including game development, math equations, and more.

Can Lua be used in Roblox?

Yes, Lua can be used in Roblox, and it is one of the primary languages supported by the platform.

What are some programs where you can edit Lua code?

Lua code can be edited in many programs such as Roblox Studio, Visual Studio Code, Atom, or any text editor like Notepad++.

What is the basic syntax for a comment in Lua?

In Lua, a comment is made with two dashes (--) followed by the comment text. For multi-line comments, use --[[ and ]].

How do you print a message in Lua?

In Lua, you use the 'print' function followed by parentheses containing the message in quotation marks, for example, 'print("Hello, World")'.

What does the 'local' keyword do in Lua?

The 'local' keyword in Lua is used to declare a variable that is local to the block of code where it is defined, not accessible globally.

How do you define a variable in Lua?

In Lua, you define a variable with 'local' followed by the variable name and then the assignment operator '=', for example, 'local hi = "Hello!"'.

What is a function in Lua and how do you define one?

A function in Lua is a block of code that can be executed multiple times. It is defined using 'local function functionName()' followed by the function's code block enclosed in 'then' and 'end'.

How can you perform simple math operations in Lua?

In Lua, you can perform simple math operations by using variables and arithmetic operators like '+', '-', '*', '/', and '^' for addition, subtraction, multiplication, division, and exponentiation, respectively.

How do you handle text input in Lua?

Text input in Lua is handled using the 'io.read' function, which reads a line from the standard input and returns it as a string that can be stored in a variable.

What is an 'if' statement and how is it used in Lua?

An 'if' statement in Lua is used for conditional execution. It checks if a condition is true and executes the code block under 'then'. If the condition is false, it executes the code block under 'else', if present.

How can you create a sales tax calculator in Lua as suggested in the tutorial?

To create a sales tax calculator in Lua, you would define variables for the price and tax rate, perform the calculation for the tax amount, and then print the original price, price with tax, and the tax amount.

Outlines

00:00

📚 Introduction to Lua Programming

This paragraph introduces the Lua programming language, highlighting its origins in 1993 and its versatility in applications beyond game development. The speaker discusses the use of Lua in Roblox, 5M Love, and other platforms, emphasizing its capabilities for mathematical operations, printing, and more. The tutorial begins by teaching how to write comments in Lua using '--', and then moves on to demonstrate how to print messages using the 'print' function. The paragraph also covers setting variables, working with functions, simple math equations, if-then statements, and text inputs. The speaker provides examples of how to declare variables with 'local', print variable values, and create functions that can be executed on demand.

05:01

🔢 Working with Variables and Functions in Lua

In this section, the focus shifts to variables and functions in Lua. The speaker explains how to declare variables using 'local' and assign values to them, demonstrating with examples like 'local hi = "hello"'. The concept of printing variable values is further explored, showing how to output both strings and numbers. Functions are introduced as blocks of code that can be executed when called, with an example function named 'howdy' that prints 'howdy partner'. The paragraph also delves into simple math equations, illustrating how to perform operations like addition, multiplication, subtraction, and division, and how to print the results. The speaker prefers the first method of handling math equations for its flexibility in changing values quickly. The discussion concludes with a brief mention of text inputs, showing how to prompt the user for their name and print a personalized greeting.

10:03

📝 Text Inputs and If Statements in Lua

This paragraph covers the process of handling text inputs in Lua, starting with opening the command prompt and running Lua files. The speaker guides through navigating to the directory containing the Lua file and executing it. Text inputs are demonstrated by printing a question to the user, reading the input using 'io.read', and storing it in a variable. The speaker also explains how to concatenate strings and variables using '..' to create personalized messages. The paragraph then moves on to if statements, explaining the syntax and logic behind conditional statements. Examples are given to illustrate how to compare variables and print different messages based on whether conditions are met. The speaker concludes with a challenge for the audience to create a sales tax calculator, providing a brief walkthrough of their own solution, which calculates and prints the original price, price with tax, and the tax amount.

Keywords

💡Lua

Lua is a lightweight, high-level programming language designed primarily for embedded use in applications. It was first released in 1993 and is known for its simplicity and flexibility. In the context of the video, Lua is introduced as a versatile language that can be used in various applications, including game development in platforms like Roblox, as well as for general programming tasks such as math equations and text processing.

💡Roblox

Roblox is a global platform that allows users to create, share, and play games created by other users. It is mentioned in the script as one of the environments where Lua can be used, highlighting its application in game development. The video suggests that Lua's capabilities extend beyond traditional programming to interactive and creative domains.

💡Comment

In programming, a comment is a piece of text in the source code that is ignored by the compiler or interpreter. Comments are used to explain the code and make it more understandable. In the video, the concept of comments in Lua is introduced with '--' being used to denote a single-line comment, and '--[[' used for multi-line comments. This is crucial for documenting code and making it easier to maintain.

💡Print

The 'print' function in Lua is used to output data to the console or standard output. It is a fundamental concept in programming for displaying results or debugging. The video script demonstrates how to use 'print' to display messages like 'hello, world' and variables, which is essential for understanding basic output operations in Lua.

💡Variable

A variable in programming is a storage location paired with an associated symbolic name, which contains some known or unknown quantity of information referred to as a value. In the video, variables in Lua are introduced with the 'local' keyword, which scopes them to the local environment. Examples given include storing strings and numbers, demonstrating how variables are used to hold and manipulate data.

💡Function

A function in programming is a block of organized, reusable code that is used to perform a single, related action. In Lua, functions are defined with the 'function' keyword. The video script explains how to create a function named 'howdy', which when called, prints 'howdy partner'. This illustrates the concept of encapsulating code for reuse and modularity.

💡Math Equations

Math equations in programming involve performing arithmetic operations such as addition, subtraction, multiplication, and division. The video script covers basic arithmetic in Lua, demonstrating how to assign values to variables and perform operations like addition ('+'), multiplication ('*'), and exponentiation. This is essential for understanding how to manipulate numerical data in Lua.

💡Text Input

Text input in programming refers to the process of receiving text from the user. In Lua, this can be achieved using the 'io.read' function. The video script shows how to prompt the user for their name and store it in a variable, demonstrating interactive communication between the program and the user, which is crucial for creating engaging user experiences.

💡If Statement

An 'if' statement is a control flow statement that allows code to be executed conditionally. In Lua, it is used to perform different actions based on certain conditions. The video script introduces 'if' statements with examples like checking if two variables are equal, demonstrating the basic logic used in decision-making in programming.

💡Sales Tax Calculator

A sales tax calculator is a tool used to calculate the total price of an item including tax. In the video, the concept is used as a practical example to demonstrate how Lua can be used for calculations. The script shows how to set variables for price and tax rate, perform the calculation, and output the results, illustrating the application of Lua in real-world scenarios.

Highlights

Introduction to the basics of Lua programming language.

Lua was first created in 1993 and is versatile for various applications including game development.

Lua can be used in platforms like Roblox, 5M Love, and more.

Lua is not limited to game development; it can also handle math equations and text printing.

Editing Lua can be done in various programs such as Roblox Studio, Visual Studio Code, Atom, or any text editor.

Explanation of how to write comments in Lua using '--' for single line and '--[[' for multi-line.

Demonstration of the 'print' function to display messages in Lua.

Introduction to variables in Lua with 'local' keyword and how to assign values.

How to use variables in print statements to output dynamic content.

Introduction to functions in Lua, defining them with 'local function' and using them.

Explanation of running functions multiple times and changing their output.

Basic math operations in Lua including addition, subtraction, multiplication, and division.

Different methods to perform and print math equations in Lua.

Guide on how to get text input from the user in Lua using 'io.read'.

How to use if statements for conditional execution in Lua with 'if', 'then', 'else', and 'end'.

Challenge for the audience to create a sales tax calculator using Lua.

Solution to the sales tax calculator challenge with step-by-step explanation.

Encouragement for practice and improvement in Lua programming.

Invitation to follow for more tutorials and to check the GitHub for code examples.

Transcripts

welcome to episode 1 of learning lua

today we're going to be talking about

the basics

some history on the programming language

lua lua was born in 1993 and lua can be

used in roblox 5m love and much much

more it's not only for game development

you can do math equations print things

and have a lot of fun with it

you can edit lua in many programs you

can do it in roblox studio visual studio

code atom any text editor or notepad

plus plus

in this tutorial you're going to be

working on printing messages setting

variables working with functions simple

math equations

if then statements and text inputs

so the first thing we're going to note

down a little basic really quick to make

a comment you do dash dash and then your

comment so i we're going to be starting

with printing so i'm gonna write

printing

and these are not part of the code but

if you don't have the dash dash or

hyphen hyphen printing

will give you an error and your code is

not gonna work and to make uh printing

with several lines you do dash dash and

then bracket bracket and enter

and now your um your comment can last

over several lines so i do this to like

uh put like credits to my work or

tutorials instead of having to do that

so printing

we're going to start by writing print

because this is saying that we're going

to do a print and then underneath our

parentheses this is basically going to

print whatever inside of here and then

we're going to put two quotation marks

inside of these quotation marks we're

going to put hello

world

and

since there's quotation marks we're

going to be outputting words you can

also print

um you could also print variables but

we're going to get into that later so

now there's two ways of writing the code

we can do run file and there we have

hello world and our second method we'll

be getting into very shortly

all right now we're going to be starting

with variables so we start off our

variable with local this means that it's

going to be stored inside of our script

and not through server scripts so we're

going to name

for example i'm going to name my

variable hi

so it's a logo in our script hi the name

of it and

our variable is going to equal so our

variable is going to mean the word so

uh quotation marks and then

hello then exclamation point you can put

anything inside of these quotation marks

and you see how the high is gray it's

not being used it will light up once we

use it another example of a variable we

can do local and then let's say we want

to put a number in our variable

number and then we could have like the

number 2 for example

and then let's say we want to print our

variable we can do

print and then parentheses because we're

printing whatever inside of our

parentheses and then we're just going to

type instead of typing hello

instead of that we're just going to type

hi

and now

it's going to print

hello where hi is and then we can also

do print and then number

and now it's going to print hello and

then 25.

now we're moving on to our functions it

functions a piece of code that can be

ran whenever you ask it to it won't run

until you specify it to run it can be

run a limited amount of times so we're

going to do local because it's going to

be stored inside of our code and instead

of print or a variable we're going to

type function

and then the name of the function so

let's name this one howdy

and then two parentheses because i'm

gonna be using a subject and then we're

gonna drop two lines

and then type end this means that we're

gonna end our function so whatever

inside of here is basically what our

function is so we can print we can do

anything we want so print

and then howdy partner

and i wouldn't so we run our function

we're going to print the words howdy

partner

so now to run our function we're going

to do howdy

and then if we run the code we will get

howdy partner

and

uh it's not going to run if we delete

heidi partner and we can do this

tons of times

and then we'll get four howdy partners

now we're going to be working a simple

math equations this is my favorite part

there's going to be three ways to type a

math equation the first thing we can do

is a local a so we're going to make a

variable that's going to equal 1 and 2.

so local a is 1

and then local b is going to equal 2.

and now

we're going to make a variable for our

answer and our answer is going to be 1

plus 2 so a plus b so local answer

equals a plus b

and we could do a plus b a times b a

minus b a divided by b

and we can do exponents and lots of more

types of equations and now that we uh

have our answer we're going to do print

and then answer

and now we have printed our answer which

is three our second way that we can do

this

is we can just do print one

two

and then that's also gonna equal three

it's just that

i don't prefer printing these because

let's say you wanna like change a number

really fast you'll have to manually

change it every time you print these

numbers

our third and final way that we can do

this is the local we can do x and y for

this one so let go x is going to equal

one

and local y is going to equal 2

and then we can print

x plus y

the shortest one is the second method

but they're all going to equal the same

thing as we can see we have three threes

i would prefer to do the first method

because you can change everything really

fast like i can change my equation

uh

so i print my answer several times the

same way instead of having to manually

change it each time

and now we're going to be moving on the

text input the first thing is we're

going to need to open up our command

prompt assuming that you have lua

installed and you're going to run this

fine and right now we're under my user

directory so i'm going to open up my

file explorer and here we have our

directory that we want

we're going to need to go to our

directory that has our file in it so

then we can run the file from command

prompt so we can type in our info so

i

am currently where i want to be so i can

copy this command

and we're going to use cd so cd stands

for change directory so cd i'm going to

type in the directory i want

and since i have cd twice we're just

gonna cd once and now we're under lua

now that we're in the directory we want

we're gonna do lua because we're using

lua and then lua

tutorial

this is now we're going to run it and

here we have our output that we wanted

so now for text inputs

we're going to print a question so we

can print

what's your

name

and then right after this we're going to

do backward slash n this means that

we're going to drop a line

so it's going to print

one text of line and that's going to

drop it for us

and now to uh get our name we're gonna

do look we're gonna create a variable

named our name

and then we're gonna equal i o dot read

parentheses then a semicolon this is

gonna read our input and store it as our

name

and now we can do

print

hi and then we're going to do a space

and this part might get a bit confusing

so after we've printed our space outside

of our quotation marks we're going to do

dot dot and the two dots mean that we're

adding on a string so you can go from

quotations to a variable to

non-quotations and it

can go on and on so it's going to be hi

and then our name and then dot dot and

then more quotation marks and we're

going to put an exclamation point in

there so now if we go to command prompt

and run that it's going to ask her name

is and i'll say ethan

and it will say hi ethan

and there you can ask other questions

and store it i've once made a story out

of it asking you questions and then it

will start as variables

now we're on to if statements so this

can be like if the number one equals the

number one then we're gonna print

something and if it does not equal one

then we're gonna print something else so

we can start with local we can do

uh first

and then we're just gonna set that to

the number six

and then local second so we're gonna set

two variables that are equivalent to six

and now we're gonna do if this is saying

if

first then

then we're going to equal equal this

means equivalent if we do one equal sign

it's going to think as a variable or

something else

so if first is equivalent to second

and then we're going to do then and now

that we're gonna drop a line

we're going to print

uh we can just print correct

and then we're gonna go back and then

else and then we're gonna print

not correct

and then we're gonna end it

just like how we ended our function so

we're gonna do end

and now if we run it

it will say correct

so now if we run it it's going to say

correct but then

let's say

we can change it to nine

so if first is equivalent so six is

equivalent to nine we run it

it's going to say not correct we can do

unequivalent

so it'd be a

squiggly and then equal

and it's gonna be correct

because six is not equivalent to nine

then we can do less than

so if six is less than nine it's correct

or it could be greater than nine

and then we can do less than error equal

to nine

and then it will output the same exact

things

now that we've finished this tutorial

we're gonna do a challenge

so what you're going to do you're going

to make you're going to make a sales tax

calculator so what you're going to do is

you're going to set a variable for the

price and the tax rate and then you're

going to make a variable that does the

math and then it will output the price

without the tax the price with the tax

and the amount of tax included i'll give

you a few minutes and then i'll show you

what i got

so here's what i got

i set a variable for our price tax rate

and our price is twenty dollars so our

tax rate in michigan is six uh and six

percent

and we're gonna

calculate our tax by uh multiplying 20

by point zero six which is

twenty six

twenty times six percent and then our

total we're just going to add our price

to our text

right

and then it will print all of what we

wanted it to print so we have our

starting price twenty dollars price with

tax twenty one dollars and twenty cents

our tax is a dollar twenty and our tax

rate is six percent

thank you so much for following this

tutorial please feel free to leave a

like and subscribe with notifications on

for our next tutorial which will uh grow

in intensity

uh please practice practice will get you

a lot better i've been doing lua for a

couple years and i've just been getting

serious with it and it's a lot of fun

once you know it

if you want the code it will be on my

github in the description and please ask

any questions in the comments have a

nice day