Recursive/deep extend/assign in Underscore.js?

Question

Is there any way to get Underscore.js extend function:

Copy all of the properties in the source objects over to the destination object, and return t

Answer 1

Kurt Milam has published a mixin that adds a deepExtend method to underscore.js. It even deals with regular expressions (if you want). Excerpt from the documentation:

Mix it in with underscore.js: _.mixin({deepExtend: deepExtend});

Call it like this: var myObj = _.deepExtend(grandparent, child, grandchild, greatgrandchild)

Notes: Keep it DRY.

This function is especially useful if you're working with JSON config documents. It allows you to create a default config document with the most common settings, then override those settings for specific cases. It accepts any number of objects as arguments, giving you fine-grained control over your config document hierarchy.