Get second level value from an object with a variable

Question

I am making a function where i give the object path in a variable. I use this function after i got my data from the database.

function find(object, path, cb) {
  return cb(object[path]);
}

var object = {user:{firstname:"bob"}};
find(object, "user", function(data){});

This works fine with objects on the first level of the object but what if i want a object from the second level or higher:

"user.firstname"

When i try to run this through the find function wil it give a not defined error. How can i improve my function?

Maybe that is just a simplified example, but I don't really see the point of the find function when you could just do `(function(data){})(object.user.firstname)`. — JJJ, May 26 '15 at 08:32
Hmm maybe a good idea to just do that. I think that i was thinking to difficult :) — Ajeo, May 26 '15 at 08:36

suvroc · Accepted Answer · 2015-05-26T08:47:59.223

1

You can do it manually by split function and iteratively executing this pattern:

var properties = path.split(".");
var value = obj;
for(prop of properties)
{
  value = value[prop];
}

edited May 26 '15 at 08:47

answered May 26 '15 at 08:35

suvroc

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when i try to use for(prop of properties) it gives a Unexpected identifier error on "prop" – Ajeo May 26 '15 at 08:44
Ow sorry i had forgot to link data to the "value" variable – Ajeo May 26 '15 at 08:47

score 1 · Answer 2 · answered May 26 '15 at 08:36

You could make your find function recursive. Besides making the path an array instead of a string gives you the option to do this for multiple layers.

function find (object, path, cb) {
    if (path.length > 1) return find(object[path.shift()], path, cb);
    return cb(object[path.pop()]);
}
var object = {user: {firstname:"bob"}};
find(object, ["user","firstname"], function (data){console.log(data)});

Get second level value from an object with a variable

2 Answers2