The question is:
What is the JavaScript method to store a multiline string into a variable like you can in PHP?
If by 'multiline string' you mean a string containing linebreaks, those can be written by escaping them using \n
(for newline):
var multilineString = 'Line 1\nLine 2';
alert(multilineString);
// Line 1
// Line 2
If you mean, how can a string be written across multiple lines of code, then you can continue the string by putting a \
backslash at the end of the line:
var multilineString = 'Line \
1\nLine 2';
alert(multilineString);
// Line 1
// Line 2