What is the JavaScript convention for no operation?

Question

What is the JavaScript convention for no operation? Like a Python pass command.

• One option is simply an empty function: function() {}

Answer 1

There is absolutely no problem or performance penalty of using Function.prototype over () => {}.

The main benefit of Function.prototype is having a singleton function rather than re-defining a new anonymous function each time. It's especially important to use a no-op like Function.prototype when defining default values and memoizing as it gives you a consistent object pointer which never changes.

The reason I'm recommending Function.prototype rather than Function is because of they're not the same:

Function() === Function()
// false

Function.prototype() === Function.prototype()
// true

Also, benchmarks from other answers are misleading. In fact, Function.prototype performs faster than () => {} depending on how you write and run the benchmark:

You can’t trust JS benchmarks << Specifically calling out benchmarks on this question.

Don't style your code from benchmarks; do whatever's maintainable and let the interpreter figure out how to optimize in the long run.