Php / Basics / Quotes - https://www.minte9.com/php/basics-quotes-14

index.php

<?php

/**
 * Define $output on multiple $lines
 * Use Herodoc syntax.
 *
 * output =
 *      She said "This is John's test"
 *      on multiple rows
 */

/**
 * SOLUTION
 */
$who = "John";
$output = <<<TEST
    She said "This is $who's test"
    on multiple rows
TEST;

echo nl2br($output);