ECMAScript Proposal: .at() method on all the built-in indexables

proposal to add an .at() method to all the basic indexable classes (Array, String, TypedArray)
— Proposal

Currently at Stage 3 and not implemented in browsers.

['a', 'b', 'c'].at(0);  // evaluates to 'a'
['a', 'b', 'c'].at(-1); // evaluates to 'c'

'string'.at(1);  // evaluates to 't'
'string'.at(-2); // evaluates to 'n'

• Proposal for an .at() method on all the built-in indexables
• Proposed specification text: Relative Indexing Method