Is table.insert(T, 1) or T[#T+1] = 1 faster

When I am appending data to a Lua table an idiom I use a lot is:

T[#T+1] = 1

I noticed a lot of people use the Lua table insert function which is like:

table.insert(T,1)

I tend to prefer the former expression since I am used to it. I was curious if there was any performance benefit one way or the other.

I wrote some test code and found that table.insert took twice as much time in the editor. This is because of the fact it creates annotations which has a little bit of overhead. Running the channel in production without the overhead of annotations and the table.insert method seems to be marginally slower than T[#T+1] = 1.

Screen shot of the logs.

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And the annotations.

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I dropped the channel into a github repo if anyone is vaguely interested 🙂 :

https://github.com/interfaceware/benchmark/blob/master/Time_Test-From-W7q9a6r73UJNnL/main.lua

Did another test comparing ipairs vs. a for loop.

https://github.com/interfaceware/benchmark/blob/master/Speed_of_ipairs-From-eYMAZvjkoaAdKK/main.lua

ipairs is slower in the editor due to annotations but faster than the simple for loop at runtime.