How do I do a multi-line string in node.js?

Question

With the rise of node.js, multi-line strings are becoming more necessary in JavaScript.

1. Is there a special way to do this in Node.JS, even if it does not work in browsers?
2. Are there any plans or at least a feature request to do this that I can support?

I already know that you can use \n\ at the end of every line, that is not what I want.

Answer 1

node v4 and current versions of node

As of ES6 (and so versions of Node greater than v4), a new "template literal" intrinsic type was added to Javascript (denoted by back-ticks "`") which can also be used to construct multi-line strings, as in:

`this is a 
single string`

which evaluates to: 'this is a\nsingle string'.

Note that the newline at the end of the first line is included in the resulting string.

Template literals were added to allow programmers to construct strings where values or code could be directly injected into a string literal without having to use util.format or other templaters, as in:

let num=10;

console.log(`the result of ${num} plus ${num} is ${num + num}.`);

which will print "the result of 10 plus 10 is 20." to the console.

Older versions of node

Older version of node can use a "line continuation" character allowing you to write multi-line strings such as:

'this is a \
single string'

which evaluates to: 'this is a single string'.

Note that the newline at the end of the first line is not included in the resulting string.

Answer 2

Multiline strings are a current part of JavaScript (since ES6) and are supported in node.js v4.0.0 and newer.

var text = `Lorem ipsum dolor 
sit amet, consectetur 
adipisicing 
elit.  `;

console.log(text);

Answer 3

What exactly are you looking for when you mean multiline strings.

Are you looking for something like:

var str = "Some \
    String \
    Here";

Which would print as "Some String Here"?

If so, keep in mind that the above is valid Javascript, but this isn't:

var str = "Some \ 
    String \
    Here";

What's the difference? A space after the \. Have fun debugging that.

Answer 4

In addition to accepted answer:

`this is a 
single string`

which evaluates to: 'this is a\nsingle string'.

If you want to use string interpolation but without a new line, just add backslash as in normal string:

`this is a \
single string`

=> 'this is a single string'.

Bear in mind manual whitespace is necessary though:

`this is a\
single string`

=> 'this is asingle string'

Answer 5

As an aside to what folks have been posting here, I've heard that concatenation can be much faster than join in modern javascript vms. Meaning:

var a = 
[ "hey man, this is on a line",
  "and this is on another",
  "and this is on a third"
].join('\n');

Will be slower than:

var a = "hey man, this is on a line\n" + 
        "and this is on another\n" +
        "and this is on a third";    

In certain cases. http://jsperf.com/string-concat-versus-array-join/3

As another aside, I find this one of the more appealing features in Coffeescript. Yes, yes, I know, haters gonna hate.

html = '''
       <strong>
         cup of coffeescript
       </strong>
       '''

Its especially nice for html snippets. I'm not saying its a reason to use it, but I do wish it would land in ecma land :-(.

Josh

Answer 6

Take a look at the mstring module for node.js.

This is a simple little module that lets you have multi-line strings in JavaScript.

Just do this:

var M = require('mstring')

var mystring = M(function(){/*** Ontario Mining and Forestry Group ***/})

to get

mystring === "Ontario\nMining and\nForestry\nGroup"

And that's pretty much it.

How It Works
In Node.js, you can call the .toString method of a function, and it will give you the source code of the function definition, including any comments. A regular expression grabs the content of the comment.

Yes, it's a hack. Inspired by a throwaway comment from Dominic Tarr.

---

note: The module (as of 2012/13/11) doesn't allow whitespace before the closing ***/, so you'll need to hack it in yourself.

Answer 7

Take a look at CoffeeScript: http://coffeescript.org

It supports multi-line strings, interpolation, array comprehensions and lots of other nice stuff.

Answer 8

If you use io.js, it has support for multi-line strings as they are in ECMAScript 6.

var a =
`this is
a multi-line
string`;

See "New String Methods" at http://davidwalsh.name/es6-io for details and "template strings" at http://kangax.github.io/compat-table/es6/ for tracking compatibility.

Answer 9

Vanilla Javascipt does not support multi-line strings. Language pre-processors are turning out to be feasable these days.

CoffeeScript, the most popular of these has this feature, but it's not minimal, it's a new language. Google's traceur compiler adds new features to the language as a superset, but I don't think multi-line strings are one of the added features.

I'm looking to make a minimal superset of javascript that supports multiline strings and a couple other features. I started this little language a while back before writing the initial compiler for coffeescript. I plan to finish it this summer.

If pre-compilers aren't an option, there is also the script tag hack where you store your multi-line data in a script tag in the html, but give it a custom type so that it doesn't get evaled. Then later using javascript, you can extract the contents of the script tag.

Also, if you put a \ at the end of any line in source code, it will cause the the newline to be ignored as if it wasn't there. If you want the newline, then you have to end the line with "\n\".