at(i, x)

Returns value at given key, index or path in an array or object or combination of both.

Where:

• i is a string, a number or an array of strings or numbers
• x is either an array or an object

Examples

Value from an array

at(1)([41, 42, 43]);
//=> 42

Value from a object

at('answer')({answer: 42});
//=> 42

Value from a nested array

at([1, 1])([[31, 32], [41, 42]]);
//=> 42

Value from an object in a nested array

at([1, 'answer'])([[{}], [{answer: 42}]]);
//=> 42

Features

• Function must be curried.
• When given an array recursively go down x
• Should avoid null pointer exception by conceding as soon as nil (i.e. either null or undefined) is detected.
• Return either nil or the value at i.
• Should not read from the prototype e.g. at('length', [1, 2, 3]) should return undefined not 3.