AppendIterator::key()

(PHP 5>=5.1.0,PHP 7)

Gets the current key

说明

publicAppendIterator::key(void) :scalar

Get the current key.

参数

此函数没有参数。

返回值

The current key if it is valid orNULLotherwise.

范例

Example#1AppendIterator::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;
    $iterator->next();
}
echo PHP_EOL;
// With foreach
foreach ($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