Wow. I can't believe template strings (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...) aren't in this list. I'm incredibly excited to start having those at my disposal.
Generally though, is it reasonable for features such as these to be included at the language level? I primarily use ES5 JavaScript so I'm used to pulling in a decent amount of modules (in this case handlebars, underscore, etc.) for things like templating.
But I will be relieved to have a language-standard solution to what feels like such a common problem for the environments in which JS is used primarily, despite the tradeoff that's made in accessibility due to feature bloat.
I'm excited for not having external libraries to handle string interpolation.
Unsafe string-munging is too easy and seductive. Doing things the safe/secure way needs to be at least as easy.
And it makes for a growable language, the way Lisp macros do. E.g. https://github.com/erights/quasiParserGenerator This can reduce the demand for feature bloat in future language standards.
Admittedly you could trivially extend the string prototype to have something more akin to string.format or printf, which was something you couldn't do in other languages for a long time, making it less of a problem.
In python you can save a string like: template = '%s is %s' and _then_ evaluate its output: print template % ('john', 'tall')
I've recently started a new project in React/Flux, and I've cut away 3 or 4 dependencies compared to previous projects by fully embracing ES2015/2016, as Babel automatically provides the necessary polyfills and compilation.
As for template strings, I think they make sense. Most programming languages have them in someway or another, like Ruby "hello #{world}" or Python 'Hello {world}'.format(world='World').
[1] https://www.reindex.io/blog/you-might-not-need-underscore/
var multi_line = 'You already \
can do this in ES5.';