if statements

if statements are Block statements.

They allow us to run a piece of code if a condition is true. The condition is considered true if the value is anything other than false or nil.

local LabTest = true   
if LabTest then   
   ProcessLabTest() -- this statement is executed   
end   

You can use Equality and inequality operators to create conditional logic. For instance:

local temperature = 98.6   
if temperature == 98.6 then   
    trace("temperature is 98.6") -- this statement is executed   
end   

You can extend if statements further by using elseif and else to define additional conditions to check.

local temperature = 104   
if temperature == 98.6 then   
    trace("temperature is 98.6")   
elseif temperature > 98.6 and temperature < 100 then   
    trace("temperature is slightly above normal")   
elseif temperature >= 100 then   
    trace("patient has a fever") -- this statement is executed   
else   
    trace("temperature is below normal")   
end   

See Using trace() function