# mergeRecursive()
The mergeRecursive method merges the given array or collection recursively with the original collection. If a string key in the given items matches a string key in the original collection, then the values for these keys are merged together into an array, and this is done recursively:
const collection = collect({
product_id: 1,
price: 100,
});
const merged = collection.mergeRecursive({
product_id: 2,
price: 200,
discount: false,
});
merged.all();
// {
// product_id: [1, 2],
// price: [100, 200],
// discount: false,
// }