How to make a separator when outputting an array so that it doesn't appear below the last element?

Question

React

I am outputting an array and I want to have a separator under each cell. But the problem is that it also appears under the bottommost object. How to fix it?

Answer 1

{thematics.map((thematic, i, a) => (
  <div>
    <div style={style1} key={thematic.id}>
      {thematic.id}
    </div>

    {i < a.length - 1 ? <div style={style2} /> : null}
  </div>
))}