[lang-ref] ( plus_equal_extends_item ) ( php )
<?php
public function testPlusEqualExtendsItem(): void
{
// No
$items = ['A', 'B', 'C', 'D', 'E'];
$items += ['F', 'G']; // This try to add key 0, 1.., but key 0, 1 already exists, so it does not add them.
$this->assertSame(['A', 'B', 'C', 'D', 'E'], $items);
}