I'm getting an error on line 5 of the code below when trying to concat two strings. I know I can simply combine the strings "a default value\n", but I would like to know why the following doesn't work as is.
<?php
    class SimpleClass
    {
        // property declaration
        public $var = 'a default value' . "\n"; //ERROR ON THIS LINE
        // method declaration
        public function displayVar() {
            echo $this->var;
        }
    }
    $a = new SimpleClass();
    echo $a->var;
    $a->displayVar();
?>
