Difference between revisions of "Basic lua: Operators"
From The Official Visionaire Studio: Adventure Game Engine Wiki
| Line 51: | Line 51: | ||
! if condition is false !! | ! if condition is false !! | ||
|- | |- | ||
| − | | <syntaxhighlight> | + | | <syntaxhighlight lang="lua"> |
local a = false | local a = false | ||
if a == false then | if a == false then | ||
| − | + | print("a = false") | |
end | end | ||
| − | </syntaxhighlight> || width=" | + | </syntaxhighlight> || width="180px" | [[File:Basic_lua_(if_queries)_(3).png|frameless|center|180px]] |
|} | |} | ||
| Line 65: | Line 65: | ||
! if condition is not met, then do else !! | ! if condition is not met, then do else !! | ||
|- | |- | ||
| − | | <syntaxhighlight> | + | | <syntaxhighlight lang="lua"> |
local a = false | local a = false | ||
if a then | if a then | ||
| − | + | print("a = true") | |
else | else | ||
| − | + | print("a = false") | |
end | end | ||
| − | </syntaxhighlight> || width=" | + | </syntaxhighlight> || width="180px" | [[File:Basic_lua_(if_queries)_(4).png|frameless|center|180px]] |
|} | |} | ||
Revision as of 17:12, 2 November 2018
Lua operators are expressions used to perform calculations or to pass arguments between different value types.
| < | Index | > |
Conditional Operators
| if | Query if something does or does not meet a certain condition. |
| else | Do something else if the query condition was not met. |
| elseif | Used to add additional if queries, if the initial query condition was not met. |
| end | This is used to close various queries or functions; there must be the same amount of end as if; except in instances where elseif has been used. |
if
| if condition is true (method 1) | |
|---|---|
local a = true
if a then
print("a = true")
end
|
_(1).png) |
| if condition is true (method 2) | |
|---|---|
local a = true
if a == true then
print("a = true")
end
|
_(2).png) |
| if condition is false | |
|---|---|
local a = false
if a == false then
print("a = false")
end
|
_(3).png) |
else
| if condition is not met, then do else | |
|---|---|
local a = false
if a then
print("a = true")
else
print("a = false")
end
|
_(4).png) |
elseif
| if condition is not met, then do elseif | |
|---|---|
local a = false
if a then
print("a = true")
elseif not a then
print("a = false")
end |
Logical Operators
| and | Allows you to check multiple conditions in a single if query. |
| or | Allows you to add an alternative if query into a single if query. |
| not | Checks if condition equals false or negative. |
and
| if condition a is true and condition b is false then | |
|---|---|
local a = true
local b = false
if a == true and b == false then
print("a = true", "b=false")
end |
or
| if condition is true or condition == true then | |
|---|---|
local a = true
if a or a == true then
print("a = true")
end |
not
| if condition is not true | |
|---|---|
local a = false
if not a then
print("a = false")
end |
Comparison Operators
| == | Equal to. |
| ~= | Does not equal. |
| >= | Greater than or equal to. |
| > | Greater than. |
| <= | Less than or equal to. |
| < | Less than. |
equal to
| if a equals 1 | |
|---|---|
local a = 1
if a == 1 then
print("a = 1")
end |
does not equal
| if a does not equal 2 | |
|---|---|
local a = 1
if a ~= 2 then
print("a = " .. a)
end |
greater than or equal to
| if a is greater than or equal to 2 | |
|---|---|
local a = 5
if a >= 2 then
print("a = " .. a)
end |
greater than
| if a is greater than 2 | |
|---|---|
local a = 3
if a > 2 then
print("a = " .. a)
end |
less than or equal to
| if a less than or equal to 2 | |
|---|---|
local a = 2
if a <= 2 then
print("a = " .. a)
end |
less than
| if a less than 2 | |
|---|---|
local a = 0
if a < 2 then
print("a = " .. a)
end |
Mathematical Operators
| + | Add |
| - | Subtract or invert |
| * | Multiply |
| / | Divide |
| ^ | Power |
| % | Remainder |
add
| 1 + 2 = 3 | |
|---|---|
local a = 1
local b = 2
local result = a + b
print( result ) |
subtract
| 3 - 2 = 1 | |
|---|---|
local a = 3
local b = 2
local result = a - b
print( result ) |
inverse
| inv of 3 = -3 | |
|---|---|
local a = 3
local result = -a
print( "original value: " .. a, "inversed value: " .. result ) |
multiply
| 2 x 2 = 4 | |
|---|---|
local a = 2
local result = a * a
print( result ) |
divide
| 10 ÷ 5 = 2 | |
|---|---|
local a = 10
local b = 5
local result = a / b
print( result ) |
power
| base of 2, power of 8 (2ⁿ) = 256 | |
|---|---|
local a, b = 2, 16
local result = a ^ b -- generate answer
-- break down power function into string result (ignore this code)
function power(i1, i2)
local val = "" -- clear string
--+--
for i = 1, i2 do -- generate the longhand math formula
if i < i2 then val = val..i1.."*" else val = val..i1 end
end
return "which is the equivalent of " .. val
end
print("power value of "..a.." & "..b.." = " .. result, power(a,b)) |
remainder
| remainder of 25 ÷ 4 = 1 | |
|---|---|
local a = 25
local b = 4
local result = a / 4
local remainder = a % b
local decimal = remainder / b
print("result: 25 ÷ 4 = " .. result, "remainder: .25 x 4 = " .. remainder, "decimal: 1 ÷ 4 = " .. decimal ) |
| < | Index | > |
