Alternate show of every 3 then every 1 item

My current code is like this which alternates between showing every 2 then every 1 item inside loop. I want it to show every 3 then every 1 item.

I use Adonis JS template engine (Edge)

<div class="column">
    @each( PRO in products )

    <div>{{ PRO.id }}</div>

    @if($loop.index % 3 !== 0 && $loop.index + 1 !== products.length)
</div>
<div class="column">
    @endif
    @endeach
</div>

Its current result is like this:

<div class="column">
    <div>1</div>
    <div>2</div>
</div>
<div class="column">
    <div>3</div>
</div>
<div class="column">
    <div>4</div>
    <div>5</div>
</div>

and I want it to become like this:

<div class="column">
    <div>1</div>
    <div>2</div>
    <div>3</div>
</div>
<div class="column">
    <div>4</div>
</div>
<div class="column">
    <div>5</div>
    <div>6</div>
    <div>7</div>
</div>

  • n % 3 !== 0 is true 2 out of 3 times, is that the issue?

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  • 1

    You should start a new div whenever index % 4 == 0 or index % 4 == 3

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  • @jaromanda-x current code is currect, but shows 2 1 2 1… I want 3 1 3 1.

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  • also using index % 4 !== 0 shows 2 1 1 2 1 1.

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  • try index % 4 > 1 – think of the current condition as index % 3 > 0 … if you had a 4:1:4:1 pattern, you’d use index %5 > 2 — a pattern emerges :p

    – 




To get a 3-1-3-1... pattern, I would reason about something like:

  1. Check if the current index (0-based) incremented by 1 (to make it 1-based and easier to reason about) is divisible by 4 or is one less than a multiple of 4.
  2. Also, validate if the current index is not the last index of the products array which would prevent creating an extra empty column <div> at the end as per my above logic.
<div class="column">
  @each(PRO in products)
    <div>{{ PRO.id }}</div>
    @if((($loop.index + 1) % 4 === 3 || ($loop.index + 1) % 4 === 0) && $loop.index + 1 !== products.length)
      </div>
      <div class="column">
    @endif
  @endeach
</div>

I have created a small snippet to test the above logic which you can refer to.

const products = Array.from({
  length: 7
}, (_, index) => ({
  id: index + 1
}));

const columns = [];
let column = [];

products.forEach((product, index) => {
  column.push(product.id);
  const newIndex = index + 1;

  if (newIndex % 4 === 3 || newIndex % 4 === 0) {
    columns.push(column);
    column = [];
  }
});

if (column.length > 0) {
  columns.push(column);
}

console.log(columns);
.as-console-wrapper { max-height: 100% !important; top: 0; }

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