Another gotcha that is not mentioned: If you have flag SKIP_EMPTY set, then key() will not reflect actual line numbers as empty lines are not accounted.
(PHP 5 >= 5.1.0, PHP 7, PHP 8)
SplFileObject::key — Get line number
Gets the current line number.
Note:
This number may not reflect the actual line number in the file if SplFileObject::setMaxLineLen() is used to read fixed lengths of the file.
此函数没有参数。
Returns the current line number.
Example #1 SplFileObject::key() example
<?php
$file = new SplFileObject("lipsum.txt");
foreach ($file as $line) {
echo $file->key() . ". " . $line;
}
?>
以上例程的输出类似于：
0. Lorem ipsum dolor sit amet, consectetur adipiscing elit. 1. Duis nec sapien felis, ac sodales nisl. 2. Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Example #2 SplFileObject::key() example with SplFileObject::setMaxLineLen()
<?php
$file = new SplFileObject("lipsum.txt");
$file->setMaxLineLen(20);
foreach ($file as $line) {
echo $file->key() . ". " . $line . "\n";
}
?>
以上例程的输出类似于：
0. Lorem ipsum dolor s 1. it amet, consectetu 2. r adipiscing elit. 3. 4. Duis nec sapien fel 5. is, ac sodales nisl 6. . 7. Lorem ipsum dolor s 8. it amet, consectetu 9. r adipiscing elit.
Another gotcha that is not mentioned: If you have flag SKIP_EMPTY set, then key() will not reflect actual line numbers as empty lines are not accounted.