[imtringued]

Actually, action for action managed languages tend to be "faster" than C in the sense that writing the equivalent program would be slower in C. However, the additional freedom leads to increased program complexity and that complexity eats into the performance budget enough to end up slower than "idiomatically" written C where the developer distilled the solution to its bare essence.

Javascript has the fastest general purpose hashmap/dictionary implementation of all programming languages but at the same time you are forced to use them all the time which overall slows the language down. Writing exactly the same code in C would be even slower since C hashmaps aren't as optimized. However, C code is rarely written like that so it's usually faster.