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PHP - Manual: AppendIterator::key

2024-12-20

AppendIterator::key

(PHP 5 >= 5.1.0, PHP 7, PHP 8)

AppendIterator::keyGets 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

示例 #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 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

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官方地址:https://www.php.net/manual/en/appenditerator.key.php

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