不能在我的fwrite（）中工作

Not sure what could be the problem.

I'm dumping data from an array $theArray into theFile.txt, each array item on a separate line.

$file = fopen("theFile.txt", "w");
foreach ($theArray as $arrayItem){
    fwrite($file, $arrayItem . '
');
}
fclose($file);

Problem is when I open theFile.txt, I see the being outputted literally. Also if I try to programmatically read the file line by line (just in case lines are there), it shows them as 1 line meaning are really not having their desired effect.

Enclose in double quotes as " "

Inside a single quote a is treated as a literal slash followed by an n, but inside a double quote it is interpreted as a newline char.

Single quotes do not process anything inside the quotes. Any '$' or escaped characters will appear exactly as they are printed with no modification (unless you run them through a function. You will have to use double quotes in order for the ' ' to appear as a line break in the file.