Pass property chain as bracket notation variable

Question

I have a function that I want to pass a variable that contains the path to an object's property. This path will change depending on where the function is being called from. I can't figure out how to save the path in a variable.

I need to save data.a.b.c in 'x'. I need to store the path to access 'c' in 'y' ( I assume using bracket notation)

function

y = [a.b.c]
calculate(data, y)   

calculate = function(data, y) { 
  x = data[y]
}

I assume you have `a.b.c` as a string? Like `y = 'a.b.c'`? If so, see this: http://stackoverflow.com/q/6491463 — gen_Eric, Oct 16 '15 at 20:39
`function resolve(path,base){return path.reduce(function(o,k,_,__){var v=o&&o[k];return v;},base||Window);} x=resolve(path.split("."), data);` — dandavis, Oct 16 '15 at 21:08

score 0 · Answer 1 · answered Oct 16 '15 at 20:44

You can't do what you'd like to do. A series of 'bracket notation' slices are pure syntax. But you can pass around functions of paths, like so, with the anonymous function passed to countInDeep:

var deep = {}
deep.a = {}
deep.a.b = {}
deep.a.b.c = {}
deep.a.b.c.count = 42

function countInDeep(func) {
  return func(deep).count
}

console.log(countInDeep(function(x) { return x.a.b.c }))
/* outputs: 42 */

Pass property chain as bracket notation variable

1 Answers1