Php/docs/appenditerator.key
AppendIterator::key
(PHP 5 >= 5.1.0, PHP 7)
AppendIterator::key — Gets the current key
说明
public AppendIterator::key ( ) : scalar
Get the current key.
参数
此函数没有参数。
返回值
The current key if it is valid or null otherwise.
范例
Example #1 AppendIterator::key() basic example
<?php$array_a = new ArrayIterator(array('a' => 'aardwolf', 'b' => 'bear', 'c' => 'capybara'));$array_b = new ArrayIterator(array('apple', 'orange', 'lemon'));$iterator = new AppendIterator;$iterator->append($array_a);$iterator->append($array_b);// Manual iteration$iterator->rewind();while ($iterator->valid()) { echo $iterator->key() . ' ' . $iterator->current() . PHP_EOL; $iterator->next();}echo PHP_EOL;// With foreachforeach ($iterator as $key => $current) { echo $key . ' ' . $current . PHP_EOL;}?>
以上例程会输出：
a aardwolf b bear c capybara 0 apple 1 orange 2 lemon a aardwolf b bear c capybara 0 apple 1 orange 2 lemon
参见
- Iterator::key() - 返回当前元素的键
- AppendIterator::current() - Gets the current value
- AppendIterator::valid() - Checks validity of the current element
- AppendIterator::next() - Moves to the next element
- AppendIterator::rewind() - Rewinds the Iterator
