1 | <?php |
||
9 | trait OperationsTrait |
||
10 | { |
||
11 | |||
12 | /** |
||
13 | * Returns the number of parameters. |
||
14 | * |
||
15 | * @return int The number of parameters |
||
16 | */ |
||
17 | 4 | public function count() |
|
21 | |||
22 | /** |
||
23 | * Returns number of items in $collection. |
||
24 | * |
||
25 | * @return int |
||
26 | */ |
||
27 | public function size() |
||
36 | |||
37 | /** |
||
38 | * @return bool |
||
39 | */ |
||
40 | public function isEmpty() |
||
44 | |||
45 | /** |
||
46 | * @return bool |
||
47 | */ |
||
48 | public function isNotEmpty() |
||
52 | |||
53 | /** |
||
54 | * @return $this |
||
55 | */ |
||
56 | 1 | public function clear() |
|
63 | |||
64 | /** |
||
65 | * Key an associative array by a field or using a callback. |
||
66 | * |
||
67 | * @param callable|string $keyBy |
||
68 | * @return static |
||
69 | */ |
||
70 | 1 | public function keyBy($keyBy) |
|
79 | |||
80 | /** |
||
81 | * @return void |
||
82 | */ |
||
83 | abstract public function rewind(); |
||
84 | } |
||
85 |
In PHP it is possible to write to properties without declaring them. For example, the following is perfectly valid PHP code:
Generally, it is a good practice to explictly declare properties to avoid accidental typos and provide IDE auto-completion: