(PHP 5 >= 5.1.0, PHP 7, PHP 8)
SplFileObject::fwrite — Write to file
   Writes the contents of data to the file
  
dataThe string to be written to the file.
length
       If the length argument is given, writing will
       stop after length bytes have been written or
       the end of data is reached, whichever comes
       first.
      
   Returns the number of bytes written, or false on error.
  
| Version | Description | 
|---|---|
| 7.4.0 | 
       The function now returns false instead of zero on failure.
       | 
     
Example #1 SplFileObject::fwrite() example
<?php
$file = new SplFileObject("fwrite.txt", "w");
$written = $file->fwrite("12345");
echo "Wrote $written bytes to file";
?>The above example will output something similar to:
Wrote 5 bytes to file