Multiline strings in JavaScript
No more string concatenation or array join!
Note that ES6 will have template string which can be multiline, but time...
var str = '' +
'<!doctype html>' +
'<html>' +
' <body>' +
' <h1>Hello world</h1>' +
' </body>' +
'</html>' +
'';var str = multiline(function(){/*
<!doctype html>
<html>
<body>
<h1>Hello world!</h1>
</body>
</html>
*/});It works by wrapping the text in a block comment, anonymous function, and a function call. The anonymous function is passed into the function call and the contents of the comment extracted.
Even though it's slower than string concat, that shouldn't realistically matter as you can still do 2 million of those a second. Convenience over micro performance always.
npm install --save multiline
- Latest Chrome
- Firefox >=17
- Safari >=4
- Opera >=9
- Internet Explorer >=6
Make sure to use /*! instead of /* when minifying to prevent the comments from being stripped.
Download manually or with a package-manager.
bower install --save multiline
component install sindresorhus/multiline
Everything after the first newline and before the last will be returned as seen below:
var str = multiline(function(){/*
<!doctype html>
<html>
<body>
<h1>Hello world!</h1>
</body>
</html>
*/});
console.log(str);Which outputs:
<!doctype html>
<html>
<body>
<h1>Hello world!</h1>
</body>
</html>
And a real-world use-case.
You can interpolate local variables and expressions by inserting them inside $[].
For example:
var name = 'Daniel';
var str = multiline(function(){/*
Hello, $[name]!
*/});
console.log(str);Will output:
Hello, Daniel!
I've also done an experiment where you don't need the anonymous function. It's too fragile and slow to be practical though.
It generates a callstack and extracts the contents of the comment in the function call.
var str = multiline(/*
<!doctype html>
<html>
<body>
<h1>Hello world!</h1>
</body>
</html>
*/);MIT © Sindre Sorhus