This backslash escape character turns special characters into string characters
var x = 'It\'s alright';
var y = "We are the so-called \"Vikings\" from the north.";
document.getElementById("demo").innerHTML = x + "<br>" + y;
We are the so-called "Vikings" from the north.
or are there any differences in implementation in PHP?
Yes. There are two significant differences with regard to the backslash as an escape:
In PHP, the use of the backslash as an escape is very different depending on whether you use a single-quoted string (
'foo') or double-quoted string (
The escape sequences are different, although there is a lot of overlap.
In PHP there's a big difference between single-quoted and double-quoted strings in terms of escape sequences (and more, see ¹ below). Details in the documentation, but in single-quoted strings, the backslash is only an escape character if the next character is a
' or a backslash; in all other cases, it's a literal backslash. So
" can appear unescaped. The escape sequences that you can use in both are exactly the same.