string as object reference to object variable

Question

var string = 'object.data.path';

That's a string that resembles a path to variable.

How can I return the corresponding variable from that string?

Something like transforming the string into return object.data.path;

The thing behind this is that the string could be much longer (deeper), like:

var string = 'object.data.path.original.result';

• Dennis: Where is the string coming from?
• tomsseisums: HTML5 data attribute name, dashes replaced with dots.

Answer 1

function GetPropertyByString(stringRepresentation) {
 var properties = stringRepresentation.split("."),
 myTempObject = window[properties[0]];
 for (var i = 1, length = properties.length; i<length; i++) {
 myTempObject = myTempObject[properties[i]];
 }
 return myTempObject;
}
alert(GetPropertyByString("object.data.path"));

this assumes that your first level object (in this case called object is global though. Alternatively, although not recommended, you could use the eval function.

• tomsseisums: Thanks! Already made a similar function, but asked in hope that there's a different way except loops..
• Šime Vidas: For each iteration, you should check if myTempObject is still an object, and only then retrieve its property...

Answer 2

Assuming you don't want to just use eval you could try something like this:

function stringToObjRef(str) {
 var keys = str.split('.'),
 obj = window;
 for (var i=0; i < keys.length; i++) {
 if (keys[i] in obj)
 obj = obj[keys[i]];
 else
 return;
 }
 return obj;
}
console.log(stringToObjRef('object.data.path.original.result'));

Uses a for loop to go one level down at a time, returning undefined if a particular key in the chain is undefined.

• tomsseisums: Thanks, award given to Chips_100 due to lower reputation. A bonus tho' for undefined return.
• nnnnnn: Thanks. (Must've been that extra time I spent thinking about the undefined test that let Chips_100 answer before me.) Regarding your comment to Chips about looking for a way to do it without loops, you can do it with function recursion...
• tomsseisums: Function recursion is still a loop, just, not a "documented" one.
• nnnnnn: Yeah, I know. And for this purpose I think a standard for loop is simpler. Some more reading that I just found from the related list on the right (includes an answer using reduce): stackoverflow.com/questions/6393943/…