How to loop inside JSX?

You can simply use Array.prototype.map with ES6 arrow function syntax.

For example, the items array of objects is mapped into an array of components:

<tbody>
  {items.map((item) => (
    <SomeComponent key={item.id} name={item.name} />
  ))}
</tbody>

But you can't iterate using for loop:

<tbody>
for (let i = 0; i < items.length; i++) {
  <SomeComponent key={items[i].id} name={items[i].name} />
}
</tbody>

This is because JSX tags are transpiled into function calls, and you can't use statements inside expressions. This may change thanks to do expressions which are stage 1 proposal.