querySelector vs getElementById

Get Element By Id

• It returns a node list which is live, meaning if you add or remove any element from the DOM the node list will update
• It is faster relative to the query selector methods

Query Selector

• It returns a node list which was available at the time of the execution

Also Read:

1. Why use javascript strict mode
2. Passing arguments from one function to another in javascript
3. Applying floats to inline elements
4. simple css reset
5. css - vertically align text