Limit items in a .map loop

Question

I would like to ask how can I limit my .map loop for example to a 5 items only because currently when I access an api it returns 20 items. but I want to display only 5. Mostly that I found is just looping all throughout the array of objects and not limiting it to a number of items.

Note: I have no control on the API because I'm just using the moviedb api

Here's my code:

var film = this.props.data.map((item) => {
  return <FilmItem key={item.id} film={item} />
});

return film;

Answer 1

You could use Array#slice and take only the elements you need.

var film = this.props.data.slice(0, 5).map((item) => {
        return <FilmItem key={item.id} film={item} />
    });

return film;

If you do not need the original array anymore, you could mutate the array by setting the length to 5 and iterate them.

Answer 2

You can also limit it by passing a second argument to a map() callback, which would be an index of an item in the loop.

const film = this.props.data?.map(
  (item, index) => 
    index < 5 && ( // <= only 5 items
      <FilmItem 
        key={item.id} 
        film={item} 
      />
    )
);

return film;

However, you probably should stick to Nina's answer unless you really need some elegancy in your code. Since I'm guessing my answer would be slower performance-wise.

References:

1. MDN: map() syntax
2. Optional Chaining

Answer 3

You could use filter() as well

var film = this.props.data.filter((item, idx) => idx < 5).map(item => {
   return <FilmItem key={item.id} film={item} />
});

return film;