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by dpe82 4052 days ago
Yes. DOM manipulation in all major browsers is implemented in C/C++. The JS engine is just a wrapper; any noticeable performance difference in DOM manipulation is almost certainly due to differences in the underlying layout engine and not in the JS engine.
1 comments
gsnedders 4052 days ago
Well, there's one way in which the JS engine effects it: how efficiently one can call into C++ from JS. Mozilla have done a lot of work to reduce the cost of that in SpiderMonkey.
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dpe82 4050 days ago
Sure, though in the grand scheme of things that penalty is pretty small when compared to the DOM operation itself. Eg. doing an appendChild() on an attached element and causing a reflow.
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gsnedders 4049 days ago
It depends a lot on what you're doing — if you're hitting fast-paths (esp. if you're dealing with out-of-tree nodes) it's entirely possible to end up with the JS/C++ trampoline being a significant part of the bottleneck, for much the same reasons as why Array.prototype.reduce can in several implementations.
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