D3 adopts the W3C Selectors API to identify document elements for selection.
Any number of operators can be applied to selected elements. These operators wrap the W3C DOM API, setting:
D3’s selection operators such as attr, style and property allow to specify the value either as:
Since each selection is simply an array, elements can also be accessed directly (e.g., [0]).
If you’re using a DOM framework like React, you probably don’t need selections (if you don’t need transitions)