Laravel - Collections - Method Merge

The merge method merges the given array or collection with the original collection. If a string key in the given items matches a string key in the original collection, the given items's value will overwrite the value in the original collection:

    
    $collection = collect(['product_id' => 1, 'price' => 100]);
    
    $merged = $collection->merge(['price' => 200, 'discount' => false]);
    
    $merged->all();
    
    // ['product_id' => 1, 'price' => 200, 'discount' => false]
	

If the given items's keys are numeric, the values will be appended to the end of the collection:

    
    $collection = collect(['Desk', 'Chair']);
    
    $merged = $collection->merge(['Bookcase', 'Door']);
    
    $merged->all();
    
    // ['Desk', 'Chair', 'Bookcase', 'Door']