There is a recent v8-users mailing list thread on this exact topic. Here's one possible explanation on perf differences between `let` and `var`: https://groups.

There is a recent v8-users mailing list thread on this exact topic. Here's one possible explanation on perf differences between `let` and `var`: https://groups.google.com/d/msg/v8-users/hsUrt4I2D98/ELsfO1e6AQAJ https://groups.google.com/d/msg/v8-users/hsUrt4I2D98/ELsfO1e...