3 replies to this topic

[GamerNebulae]

I have been talking to my dad and asked him what exactly nil was. He wasn't exactly sure and maybe you guys can answer me on that one. What exactly is the difference between nil and null and when is something nil or null?

[theoriginalbit]

a variable is nil when a value has not been assigned to it... nil is a keyword, just like null is a keyword in other languages, used to mean the same thing...

also as makerimages stated in Lua nil actually resolves to false, meaning that your if statements could be structured like so

if someVar then
 --# do something
end

instead of

if someVar ~= nil then
  --# do something
end

[Lyqyd]

The only distinctions between nil and null are their respective spellings and which languages they're used in.

[immibis]

In Lua, nonexistent table entries act as if they have the value nil. It's also the default value for global variables (which are really table entries) and local variables.

t = {test=123}
print(tostring(t["test"])) -- prints: 123
print(tostring(t["hello"])) -- prints: nil

print(tostring(asdf)) -- prints: nil

local x
print(tostring(x)) -- prints: nil