Variables - Revision history

Lyqyd: Add modulus operator, fix formatting for other arithmetic operators.

2013-08-14T19:56:51Z

Add modulus operator, fix formatting for other arithmetic operators.

AfterLifeLochie: Ported to the Tutorial template

2012-12-01T13:23:15Z

Ported to the Tutorial template

180.119.115.40: /* What have we learned? */

2012-11-03T05:51:06Z

‎What have we learned?

77.168.161.231: typo

2012-08-17T16:33:44Z

typo

My hat stinks: /* What do variables look like? */

2012-05-22T09:06:31Z

‎What do variables look like?

My hat stinks: /* What do variables look like? */

2012-05-19T18:13:53Z

‎What do variables look like?

My hat stinks: /* What do variables look like? */

2012-05-19T18:12:27Z

‎What do variables look like?

My hat stinks at 18:08, 19 May 2012

2012-05-19T18:08:05Z

My hat stinks: /* What do variables look like? */

2012-05-18T19:47:35Z

‎What do variables look like?

My hat stinks: Created page with "Category:Tutorials This is a tutorial page for Variables and their function. == What are Variables? == Variables are one of the fundamental building blocks of all coding..."

2012-05-17T22:29:04Z

Created page with "Category:Tutorials This is a tutorial page for Variables and their function. == What are Variables? == Variables are one of the fundamental building blocks of all coding..."

New page

[[Category:Tutorials]]
This is a tutorial page for Variables and their function.

== What are Variables? ==

Variables are one of the fundamental building blocks of all coding languages. Variables are just as they sound, they can store a changeable value.

== What do variables look like? ==

Variables will usually be defined near the start of a script or function (Functions will be taught in a later tutorial), as this will make them easy to edit later if required. Variables can be defined in a number of different ways, reliant on the type of data that is being stored.

; String values
String variables can store any text or "string" that you will use in your script
Strings can be defined as follows
local Text = 'This is a string!'
local MoreText = "This is also a string!"

; Number values
Number variables can store any number used in the script, as well as perform calculations with them.
Numbers can be defined as follows
local Number = 1
local AnotherNumber = 2

; Boolean values
Boolean variables are simply a "True or False?" variable. They can be either true or false, but nothing else. Boolean values are usually used for conditional statements, which will be covered in a later tutorial.
Boolean variables can be defined as follows
local Bool = true
local Bool2 = false
Note that "true" and "false" are case sensitive.

; Nil values
Nil values are values that are currently storing nothing. Usually you will not explicitly set a variable to nil, as it acts similar to a "false" boolean. All variables are nil by default.
local Variable = nil
Note that "nil" is case sensitive

; Table values
Table variables are variables that can store any other variables, including more tables. They will be described in more depth in a later tutorial.
Tables can be defined as follows
local EmptyTable = {}
local Table = {1,2,3,4}
local AnotherTable = {"This table", "Contains", 3, {"Types of variables!"} }

; Function values
Although not often considered variables, Lua functions can act the same way as other more standard variables. functions will be described in more detail in a later tutorial.
functions can be defined as follows
local DoStuff = function() end
function AnotherFunction() end

local DoStuff2 = function()
write("Function!\n")
end
function AnotherFunction2()
write("Another function!\n")
end
Function and table variables are usually defined over multiple lines due to the length of them. In Lua, a new line does not mark any functionality and is used purely for readability.

Unlike many other languages, Lua allows for variable's data types to be changed as you go, easily overwriting, for example, a string with a number.
local Variable = "String!" --The variable is a string
Variable = 1 --The variable is now a number

== What is "local" and why is it useful? ==
You may have noticed the use of "local" in the above declarations. "local" simply states that the variable being defined should only be used in this script or function. You only need to write local for the first time you set a variable, then it will assume every other time you use the variable afterwords it is the local variable. If you use or set a variable without using local, it will try and use or set a global variable which can be used and modified by other scripts.

Although it likely won't be an issue when you are using ComputerCraft, it is advisable to use local variables and functions when possible, so they will not be unintentionally edited by other functions or scripts.

==What have we learned?==
*Variables can store values
*Variables store different types of values
*Variables can be defined in different ways
*An overview of what different variable types do
*Use "local" to use locally

@@ Line 38: / Line 38: @@
   local AnotherNumber = 2
 Lua supports the following mathematical functions:
-*Addition (+) ''1+1=2''
+*Addition (+) ''1+1 = 2''
-*Subtraction (-) ''2-1=1''
+*Subtraction (-) ''2-1 = 1''
-*Multiplication (*) ''2*2 =4''
+*Multiplication (*) ''2*2 = 4''
-*Division (/) ''2/2 =1''
+*Division (/) ''2/2 = 1''
-*Power (^) ''2^3 =8''
+*Modulus (%) ''5%2 = 1''

@@ Line 97: / Line 97: @@
 *An overview of what different variable types do
 *Use "local" to use variables locally
-*Muitlple values may be assigned at once
+*Multiple values may be assigned at once

← Older revision		Revision as of 09:06, 22 May 2012
Line 31:		Line 31:
	local Number = 1		local Number = 1
	local AnotherNumber = 2		local AnotherNumber = 2
		+	Lua supports the following mathematical functions:
		+	*Addition (+) ''1+1=2''
		+	*Subtraction (-) ''2-1=1''
		+	Multiplication () ''2*2 =4''
		+	*Division (/) ''2/2 =1''
		+	*Power (^) ''2^3 =8''

← Older revision		Revision as of 18:12, 19 May 2012
Line 16:		Line 16:
	local Text = 'This is a string!'		local Text = 'This is a string!'
	local MoreText = "This is also a string!"		local MoreText = "This is also a string!"
		+	String values have the unique ability to be concatenated (One added to the end of the other). To do this, simply enter a ".." between the two strings or variables.
		+	local Start = "This is"
		+	local Middle = " all part of "
		+	local End = "one sentence!\n"
		+
		+	Start = Start..Middle
		+
		+	write(Start..End)
		+	This will write "This is all part of one sentence!"

@@ Line 1: / Line 1: @@
 [[Category:Tutorials]]
-This is a tutorial page for Variables and their function.
+{{Tutorial
 == What are Variables? ==

@@ Line 81: / Line 81: @@
 == What is "local" and why is it useful? ==
-You may have noticed the use of "local" in the above declarations. "local" simply states that the variable being defined should only be used in this script or function. You only need to write local for the first time you set a variable, then it will assume every other time you use the variable afterwords it is the local variable. If you use or set a variable without using local, it will try and use or set a global variable which can be used and modified by other scripts.
+You may have noticed the use of "local" in the above declarations. "local" simply states that the variable being defined should only be used in this script or function. You only need to write local for the first time you set a variable, then it will assume every other time you use the variable afterwards it is the local variable. If you use or set a variable without using local, it will try and use or set a global variable which can be used and modified by other scripts.
 Although it likely won't be an issue when you are using ComputerCraft, it is advisable to use local variables and functions when possible, so they will not be unintentionally edited by other functions or scripts.

@@ Line 12: / Line 12: @@
 ; String values
-String variables can store any text or "string" that you will use in your script
+String variables can store any text or "string" that you will use in your script. Strings can be defined as follows
 Strings can be defined as follows
   local Text = 'This is a string!'
   local MoreText = "This is also a string!"
@@ Line 57: / Line 56: @@
 ; Function values
-Although not often considered variables, Lua functions can act the same way as other more standard variables. functions will be described in more detail in a later tutorial.
+Although not often considered variables, Lua functions can act the same way as other more standard variables. Functions will be described in more detail in a later tutorial.
 functions can be defined as follows
    local DoStuff = function() end

@@ Line 70: / Line 70: @@
 Although it likely won't be an issue when you are using ComputerCraft, it is advisable to use local variables and functions when possible, so they will not be unintentionally edited by other functions or scripts.
 ==What have we learned?==
@@ Line 76: / Line 82: @@
 *Variables can be defined in different ways
 *An overview of what different variable types do
-*Use "local" to use locally
+*Use "local" to use variables locally

@@ Line 51: / Line 51: @@
 functions can be defined as follows
    local DoStuff = function() end
-   function AnotherFunction() end
+   local function AnotherFunction() end
    local DoStuff2 = function()
      write("Function!\n")
    end
-   function AnotherFunction2()
+   local function AnotherFunction2()
      write("Another function!\n")
    end