sum() публичный Метод

Get the sum of the given values.
public sum ( Closure | string $callback ) : mixed
$callback Closure | string
Результат mixed
Документация по классу Collection
Пример #1
0
 public function testGettingSumFromEmptyCollection()
 {
     $c = new Collection();
     $this->assertEquals(0, $c->sum('foo'));
 }