PHP newline not working in text file

Question

I am using the PHP code:

$numberNewline = $number . \'\\n\';
fwrite($file, $numberNewline);

to write $number to a file.

For some reason

Answer 1

Use PHP_EOL. PHP_EOL is platform-independent and good approach.

$numberNewline = $number .PHP_EOL;
fwrite($file, $numberNewline);

PHP_EOL is cross-platform-compatible(DOS/Mac/Unix).