Lua is imilar to JavaScript in that respect, and LuaJIT2 has effectively solved this problem for Lua. Code that's perfectly dynamic is almost on par with C, with variables switching type from int to double to string as needed. With essentially no restrictions on what you use.
JavaScript is more braindamaged in its dynamicness, so it's harder to write something like LuaJIT2 for JavaScript -- but it's not impossible.
JavaScript is more braindamaged in its dynamicness, so it's harder to write something like LuaJIT2 for JavaScript -- but it's not impossible.