PHP - write to file at end of each line

Question

Assume I already have a text file which looks like:

sample.txt

This is line 1.
This is line 2.
This is line 3.
.
.
.
This is line n.

---

How can I append data from an array to the END of each line?

The following ONLY attaches to the line following the last line.

appendThese = {"append_1", "append_2", "append_3", ... , "append_n"};

foreach($appendThese as $a){

   file_put_contents('sample.txt', $a, FILE_APPEND); //Want to append each array item to the end of each line
}

---

Desired Result:

    This is line 1.append_1
    This is line 2.append_2
    This is line 3.append_3
    .
    .
    .
    This is line n.append_n

Answer 1

Do this :

<?php
$file = file_get_contents("file.txt");
$lines = explode("\n", $file);
$append= array("append1","append2","append3","append4");
foreach ($lines as $key => &$value) {
    $value = $value.$append[$key];
}
file_put_contents("file.txt", implode("\n", $lines));
?>