Hidden Methods Intermediate Since Laravel 8.x

Collection::sliding()

Create a sliding window of overlapping chunks from a collection — perfect for moving averages, comparisons, and sequential analysis.

Overview

sliding() returns a new collection of overlapping "windows" of a given size. Unlike chunk() which creates non-overlapping groups, sliding() moves one item at a time (or by a custom step), giving you every consecutive sub-sequence.

Usage

$collection = collect([1, 2, 3, 4, 5]);

$collection->sliding(2);
// [[1, 2], [2, 3], [3, 4], [4, 5]]

$collection->sliding(3);
// [[1, 2, 3], [2, 3, 4], [3, 4, 5]]

With a custom step size:

$collection->sliding(size: 3, step: 2);
// [[1, 2, 3], [3, 4, 5]]

Real-World Example

Calculating a 7-day moving average:

$dailyRevenue = collect($revenueData); // 30 days of data

$movingAverages = $dailyRevenue
    ->sliding(7)
    ->map(fn ($window) => [
        'date' => $window->last()['date'],
        'average' => $window->avg('amount'),
    ]);

Detecting consecutive duplicate values:

$logs = collect($statusLogs);

$repeated = $logs->sliding(2)
    ->filter(fn ($pair) => $pair->first()['status'] === $pair->last()['status'])
    ->map(fn ($pair) => $pair->first());

When to Use

  • Moving averages, rolling sums, or time-series analysis
  • Finding consecutive patterns in sequences
  • Comparing each item with its neighbors
  • Signal processing or data smoothing
Read the Laravel documentation

Tags

Collections