JavaScript is slow if you need to do things that JavaScript can’t do, such as
- lots of stack-allocated objects/arrays (in JavaScript you have to heap-allocate them)
- hash maps with non-primitive types as keys (in JavaScript you have to serialize them to a string)
- count trailing zero bits (in JavaScript you have to use a lookup table)
Do you have a link to the research? I’m a math educator and I’d like some good materials for encouraging my students.