JavaScript: Object Rename Key

Question

Is there a clever (i.e. optimized) way to rename a key in a javascript object?

A non-optimized way would be:

o[ new_key ] = o[ old_key ]; delete o[ old_key ]; 

Answer 1

The most complete (and correct) way of doing this would be, I believe:

if (old_key !== new_key) {     Object.defineProperty(o, new_key,         Object.getOwnPropertyDescriptor(o, old_key));     delete o[old_key]; } 

This method ensures that the renamed property behaves identically to the original one.

Also, it seems to me that the possibility to wrap this into a function/method and put it into Object.prototype is irrelevant regarding your question.

Answer 2

If you're mutating your source object, ES6 can do it in one line.

delete Object.assign(o, {[newKey]: o[oldKey] })[oldKey]; 

Or two lines if you want to create a new object.

const newObject = {}; delete Object.assign(newObject, o, {[newKey]: o[oldKey] })[oldKey];