SplFileObject::next

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

SplFileObject::next — Read next line

说明

public SplFileObject::next(): void

Moves ahead to the next line in the file.

参数

此函数没有参数。

返回值

没有返回值。

范例

示例 #1 SplFileObject::next() example


<?php
// Read through file line by line
$file = new SplFileObject("misc.txt");
while (!$file->eof()) {
    echo $file->current();
    $file->next();
}
?>

参见

SplFileObject::current() - Retrieve current line of file
SplFileObject::key() - Get line number
SplFileObject::seek() - Seek to specified line
SplFileObject::rewind() - Rewind the file to the first line
SplFileObject::valid() - Not at EOF

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User Contributed Notes 2 notes

down

Jonnycake ¶

7 years ago


Quick note when using next(), it appears that you have to already be at the end of the line in order for it to hop to the next one.  I realized this while attempting to do a lineCount implementaiton like the following:

<?php
  function lineCount($file)
  {
     $x=0;
     while(!$file->eof()) {
          $x++;
          $file->next();
     }
     return $x;
  }
  $file=new SplFileObject("something");
  echo lineCount($file);
?>

It ended up in an infinite loop.  The solution was to just call fgets()/current() in the loop, although it wasn't being used anywhere so the following works:

<?php
  function lineCount($file)
  {
     $x=0;
     while(!$file->eof()) {
          $file->current();
          $x++;
          $file->next();
     }
     return $x;
  }
  $file=new SplFileObject("something");
  echo lineCount($file);
?>

down

-2

quijote dot shin at gmail dot com ¶

5 years ago


As @Jonnycake  pointed there is no documentation about the following behavior of  next();

You need to call current() to really move forward without the need of a source loop.

Be:
<?php
$file = new SplFileObject("file.txt");

echo PHP_EOL . $file->current();
$file->next();
$file->next();
$file->next();
echo PHP_EOL . $file->current(); // 2nd line of the file

?>

<?php
$file = new SplFileObject("file.txt");

echo PHP_EOL . $file->current();
$file->next(); $file->current();
$file->next(); $file->current();
$file->next(); 
echo PHP_EOL . $file->current(); // be the 4th line of the file

?>

Honestly, I don't know if it is  waste of memory and/or CPU .

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官方地址：https://www.php.net/manual/en/splfileobject.next.php

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PHP官方手册 - 互联网笔记

SplFileObject::next

说明

参数

返回值

范例

参见

User Contributed Notes 2 notes