Php/docs/appenditerator.construct
AppendIterator::__construct
(PHP 5 >= 5.1.0, PHP 7)
AppendIterator::__construct — Constructs an AppendIterator
说明
public AppendIterator::__construct ( )
Constructs an AppendIterator.
参数
此函数没有参数。
返回值
没有返回值。
范例
Example #1 Iterating AppendIterator with foreach
<?php$pizzas = new ArrayIterator(array('Margarita', 'Siciliana', 'Hawaii'));$toppings = new ArrayIterator(array('Cheese', 'Anchovies', 'Olives', 'Pineapple', 'Ham'));$appendIterator = new AppendIterator;$appendIterator->append($pizzas);$appendIterator->append($toppings);foreach ($appendIterator as $key => $item) { echo $key . ' => ' . $item . PHP_EOL;}?>
以上例程会输出：
0 => Margarita 1 => Siciliana 2 => Hawaii 0 => Cheese 1 => Anchovies 2 => Olives 3 => Pineapple 4 => Ham
Example #2 Iterating AppendIterator with the AppendIterator API
<?php$pizzas = new ArrayIterator(array('Margarita', 'Siciliana', 'Hawaii'));$toppings = new ArrayIterator(array('Cheese', 'Anchovies', 'Olives', 'Pineapple', 'Ham'));$appendIterator = new AppendIterator;$appendIterator->append($pizzas);$appendIterator->append($toppings);while ($appendIterator->valid()) { printf( '%s => %s => %s%s', $appendIterator->getIteratorIndex(), $appendIterator->key(), $appendIterator->current(), PHP_EOL ); $appendIterator->next();}?>
以上例程会输出：
0 => 0 => Margarita 0 => 1 => Siciliana 0 => 2 => Hawaii 1 => 0 => Cheese 1 => 1 => Anchovies 1 => 2 => Olives 1 => 3 => Pineapple 1 => 4 => Ham
注释
Caution
When using iterator_to_array() to copy the values of the AppendIterator
into an array, you have to set the optional use_key argument to
false. When use_key is not false any keys reoccuring in inner
iterators will get overwritten in the returned array. There is no way to preserve the original keys.
