Lua - Functions

Published 2014/03/05 by Admin in LUA

Create a function without parameters

function myFirstLuaFunction()

print("My first lua function was called")

end

Calling the function

myFirstLuaFunction()

 

Create a function with a return value

function mySecondLuaFunction()

return "string from my second function"

end

Calling the function

a=mySecondLuaFunction()

print(a)

 

Create a function with multiple parameters and multiple return values

function myFirstFunctionWithMultipleReturnValues(a,b,c)

return a,b,c,"My first lua function with multiple return values", 1, true

end

Calling the function

a,b,c,d,e,f = myFirstFunctionWithMultipleReturnValues(1,2 , "three")

print(1,b,c,d,e,f)


Lua - break statement

Published 2014/03/05 by Admin in LUA

The break statement is used to exit a loop.

a = 0

while true do

a = a+1

if a==10 then 

break

end

end

print(a)

Output:

10


Lua - Print tables

Published 2014/03/03 by Admin in LUA
Tags: , , , , ,

Printing out tables is not as simple as printing a normal variable. To print a table we must first get each element in the table by itself. We do this by using the "pairs" keyword.

a={1,2,3,4,"five","elephant","mouse"}

for i,v in pairs(a) do print(i,v) end

Output:

1     1

2     2

3     3

4     4

5     five

6     elephant

7     mouse


Lua - for statement

Published 2014/03/03 by Admin in LUA

The for statement allows you to repeat the same task for a predefined amount of iterations.

 

Count from 1 to 4 in intervals of 1

for a=1,4 do io.write(a) end

print()

Output:

1234

 

Count from 1 to 6 in intervals of 3

for a=1,6,3 do io.write(a) end

print()

Output:

14

 

Sequential iteration form

for key,value in pairs({1,2,3,4}) do print(key,value) end

Output:

1     1

2     2

3     3

4     4



Lua - repeat until statement

Published 2014/03/03 by Admin in LUA

The repeat until statement allows you to perform a repetitive task until a certain condition is met.

a=0

repeat

a=a+1

print(a)

until a==5

Output:

1

2

3

4

5


Lua - while statement

Published 2014/03/03 by Admin in LUA

The while statement allows you to repeat a task until a certain condition is met.

a=1

--this is a comment

while a~= 5 do  -- Lua uses ~= to mean not equal 

a=a+1

io.write(a.." ")

end

Output:

2 3 4 5


Lua - Conditional Assignment

Published 2014/03/03 by Admin in LUA
Tags: , , , , ,

We are able to take a bit of the long-windedness of the "if, else" statement away by using conditional assignment.

a=1

b=(a==1) and "one" or "not one"

The code above is the same as the code below.

a=1

if a==1 then

b = "one"

else 

b = "not one"

end

As you can see conditional assignment removes a lot of unnecessary code.


Lua - if elseif else statement

Published 2014/03/03 by Admin in LUA

The combination of if, elseif, and else now give us more than 2 options, we can have as many cases as are required.

c=3

if c==1 then

print("c is 1")

elseif c==2 then

print("c is 2")

else

print("c isn't 1 or 2, c is "..tostring(c))

end


Lua - if else statement

Published 2014/03/03 by Admin in LUA
Tags: , , , ,

The if statement coupled with the else keyword now gives us 2 options that allows for multiple outcomes based on the conditions we are testing against.

b="happy"

if b=="sad" then

print("b is sad")

else

print("b is not sad")

end


Lua - if statement

Published 2014/03/03 by Admin in LUA
Tags: , , , ,

The if statement in coding is used for logic and sequential state machine control. Basically it helps the application decide what to do next based on a set of values that need to correspond to the logic flow requirement.

a = 1

if a==1 then

print ("a is one")

end


my coding

This is a collection of all the coding gems I have found and would like to share with the world!