如何在php中创建对象列表

Question

I am .net developer just started to work on PHP project with Laravel framework. In .net, we can create List frequently. What is the alternate way of doing same in PHP. After that, I want to pass that list as method parameter & accessing list items. I searched on google but can't find anything suitable. I know this may be very basic question from the view point of PHP developers. But I am still in confusion & can not proceed with my work.

eg in .net code, we create list object as -

public List<ReaderInfo> readerInfo = null;

To pass that list object in method -

InitReaderInfo(readerInfo);

Method definition is written as -

public void InitReaderInfo(List<ReaderInfo> reader)

Now, I want to convert the same in PHP. Any suggestion?

Answer 1

PHP is not a strong type language. It also doesn't support generics or generic methods. That general means you cannot write this:

public List<ReaderInfo> readerInfo = null;

or this:

public void InitReaderInfo(List<ReaderInfo> reader)

There is no easy way to enforce type to list elements just by defining it. However, PHP supports argument types declaration so you can do this:

<?php

class Thing {
  private $name;
  public function __construct($name) {
    $this->name = $name;
  }
  public function __toString() {
    return $this->name;
  }
}

class Fruit extends Thing {}

class ThingList {
  private $list;
  public function __construct(Thing ...$list) {
    $this->list = $list;
  }
  public function __toString() {
    return array_reduce($this->list, function ($carry, $item) {
      return $carry . $item . "
";
    }, '');
  }
}

function PrintThings(ThingList $list) {
  // ... do something to the thing list
  echo $list;
}

?>

in order to get better type-safety like this:

<?php

// declare a list of thing
$things = new ThingList(
  new Thing("apple"),
  new Fruit("orange")
);

PrintThings($things);

?>

If you're talking about Laravel specific solution, I suggest you to look at the jcrowe/type-safe-collection library, which you can do similar thing with a lot less labour.