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Marcos Gonzales
3,688 PointsWhy are we using getElementsByTagName instead of querySelector? Is there a valid reason?
I am curious if there is a reason why because both of them work.
1 Answer
![Jennifer Nordell](https://uploads.teamtreehouse.com/production/profile-photos/5432702/micro_jen-square.jpg)
Jennifer Nordell
Treehouse TeacherHi there! You're correct that they both work. However, a querySelector
is best used for really tricky selections of the DOM and getElementsBy...
is better when used for simpler selections. The querySelector
has a bit of additional parsing by the browser under the hood which can have a bit of a performance cost associated with it.
Here is a very simple jsperf test that I made where you can test the performance cost on a simple selection. You might also be interested in reading another discussion about this on this thread.
Hope this helps!