如何在 PHP 中创建对象列表或数组？
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How do I create a list or an array of objects in PHP?
提问by OneSmartGuy
I'm a .net programmer vb & c#, but I can't seem to figure out how to get my objects into a list or array in PHP.
我是 .net 程序员 vb & c#，但我似乎无法弄清楚如何将我的对象放入 PHP 中的列表或数组中。
var mylist = new List<myobject>();
mylist.add(myobject1);
mylist.add(myobject2);
What I have tried.
Products being a property for a collection of orderitems:
我尝试过的。
产品是以下集合的属性orderitems：
$this->Products = getOrderItems();
public function getOrderItems()
{
$items = array();
$count = 0;
// connect to db, query.....
while($row = mysql_fetch_array($result, MYSQL_BOTH)){
$count++;
$items[$count] = ($row);
}
echo 'Count of Order Items...' . $count;
return $items;
}
Am I even close?
我什至接近吗？
回答by moo
$items = array();
while($row = mysql_fetch_array($result, MYSQL_BOTH)) {
$items[] = $row;
}
echo 'Count of Order Items...', count($items);
回答by stefs
$this->Products = getOrderItems();is legal in PHP, but it refers to the (global) functiongetOrderItems()instead of the class method. class methods and variables always have to be prefixed with$this->(orself::, if they're static vars) when called from inside the class.
in your sample-code, you have that wrong. getOrderItems is defined as class method, but your call is not$this->-scoped, thus php assumes a function. it should throw anfunction not found-error.the
[]notation adds an element to the end of an array.the index of the first element in your sample code is 1 (isn't that the standard case for VB?). php normally starts at 0 - though it's possible (because php-arrays are not real arrays) to start at arbitrary indices i'd recommend to stick with zero.
mysql_fetch_arrayis an ancientway of working with mysql. nowadays you're better of with mysqli or (even better) PDO.(...) a list or array in php.
lists, arrays, stacks, whatever: in php everthing is an ordered map (misleadingly called array):
PHP: Arrays: An array in PHP is actually an ordered map. A map is a type that associates values to keys. This type is optimized for several different uses; it can be treated as an array, list (vector), hash table (an implementation of a map), dictionary, collection, stack, queue, and probably more. As array values can be other arrays, trees and multidimensional arrays are also possible.
$this->Products = getOrderItems();在 PHP 中是合法的，但它指的是（全局）函数getOrderItems()而不是类方法。从类内部调用时，类方法和变量总是必须以$this->（或self::，如果它们是静态变量）为前缀。
在您的示例代码中，您错了。getOrderItems 被定义为类方法，但您的调用不是$this->范围的，因此 php 假定一个函数。它应该抛出一个function not found错误。该
[]表示法将一个元素添加到数组的末尾。示例代码中第一个元素的索引是 1（这不是 VB 的标准情况吗？）。php 通常从 0 开始 - 尽管有可能（因为 php 数组不是真正的数组）从任意索引开始，我建议坚持使用零。
mysql_fetch_array是一种使用 mysql的古老方式。现在你更喜欢使用 mysqli 或（甚至更好）PDO。(...) php 中的列表或数组。
列表、数组、堆栈等等：在 php 中，一切都是有序映射（误导性地称为数组）：
PHP: Arrays: PHP 中的数组实际上是一个有序映射。映射是一种将值与键相关联的类型。此类型针对多种不同用途进行了优化；它可以被视为数组、列表（向量）、哈希表（映射的实现）、字典、集合、堆栈、队列等等。由于数组值可以是其他数组，树和多维数组也是可能的。
update:
更新：
sorry, i haven't got enough time right now to explain the finer nuances of pdo/mysqliover mysql.
抱歉，我现在没有足够的时间来解释pdo/ mysqli与mysql 之间的细微差别。
so here are just the basics:
所以这里只是基础知识：
oop:pdo and mysqli are object oriented (tough mysqli got functional aliases)
prep statements:most important: pdo/mysqli got prepared statements. that means, you first prepare the query with placeholders once, then fill in the values later (without the need to prepare the query a second time). this approach has 3 obvious advantages:
performance:it's faster, because the database only has to analyze, compile and optimize the query once (at least with complex queries)
security:no need for quoted strings (happens automatically!), making sql-injection attacks harder
maintainability:the logic and data part of the query are separated, thus easier to read and you don't have to do a lot of string concenation
driver driven:pdo is not database specific. there are several supported db-systems, making it easier to port your code to other db-backends (but it's not an db-abstraction layer like ODBC, so the SQL still has to be compatible)and increasing reusability
oop：pdo 和 mysqli 是面向对象的（艰难的 mysqli 有功能别名）
准备语句：最重要的是：pdo/mysqli 得到了准备好的语句。这意味着，您首先使用占位符准备一次查询，然后稍后填写值（无需再次准备查询）。这种方法有 3 个明显的优点：
性能：更快，因为数据库只需要分析、编译和优化一次查询（至少对于复杂的查询）
安全性：不需要带引号的字符串（自动发生！），使 sql 注入攻击更加困难
可维护性：查询的逻辑部分和数据部分是分离的，因此更易于阅读，您不必进行大量的字符串合并
驱动程序驱动：pdo 不是特定于数据库的。有几个受支持的数据库系统，可以更轻松地将代码移植到其他数据库后端（但它不是像 ODBC 那样的数据库抽象层，因此 SQL 仍然必须兼容）并提高可重用性
of course, there's a lot more to it
当然，还有很多
回答by John Fiala
What orlandu63 posted is correct - using $items[] = $rowmeans that $row is appended numerically as the next element of $items.
orlandu63 发布的内容是正确的 - 使用$items[] = $row意味着 $row 以数字方式附加为 $items 的下一个元素。
Another option is that if there's an id field in $row, you can do $items[$row->id] = $row;, which has the advantage of indexing your array and making it easier to find a given item.
另一种选择是，如果 $row 中有一个 id 字段，您可以执行$items[$row->id] = $row;，这具有索引数组并更容易找到给定项目的优点。
I really suggest reading through http://www.php.net/manual/en/language.types.array.php, which will explain to you some of the cool things PHP allows with arrays.
我真的建议通读http://www.php.net/manual/en/language.types.array.php，它会向您解释 PHP 允许使用数组的一些很酷的东西。
