Lua and switch statements

[smurfier]

While Lua itself does not have support for Switch Statements there is a method to emulate them.

Without Switch Statements we need to result to long if/then/elseif statements which are sometimes inefficient and create redundancies.

Code: Select all

TestValue = 'Joe'

if string.lower(TestValue) == 'joe' then
	Result = 33
elseif string.lower(TestValue) == 'bob' then
	Result = 68
elseif string.lower(TestValue) == 'peter' then
	Result = 42
elseif string.lower(TestValue) == 'jane' then
	Result = 16
else
	Result = 0
end

A switch style statement can sometimes reduce the amount of code quite a bit.

Code: Select all

TestValue = 'Joe'

Switch = {
	joe = 33,
	bob = 68,
	peter = 42,
	jane = 16,
}

Result = Switch[string.lower(TestValue)] or 0

If we want to take an action instead of just returning a value, things start to look a bit different.

Code: Select all

TestValue = 'Joe'

Switch = {
	joe = function() return 33 end,
	bob = function() return 68 end,
	peter = function() return 42 end,
	jane = function() return 16 end,
}

local func = Switch[string.lower(TestValue)] or function() return 0 end

Result = func()

Since we have to test whether the value exists or not we use the func variable to store our function for one line.