expose unknown JavaScript object methods from third-party code

Question

I am looking for a way to expose the type and methods of an unknown JavaScript object.

I am implementing third-party code that has limited documentation for their methods, so I do not have access to any documentation that would tell me what sort of object I should expect in response.

Is there any way to ascertain what type of object this is and expose the methods it contains?

for (var i = 0; i <= response.length - 1; i++) {
     console.log(response.i);
}

The output in the Firebug Console:

response: [object Object],[object Object],[object Object],....

Answer 1

You may want to try

console.dir(response);

It lists all the object's properties, and their respective types are indicated by colorization:

• red key: Constructor functions
• green key: methods
• black key: other
  • red value: string
  • green value: object
  • blue value: boolean
  • gray value: undefined/null

This list is not exhaustive, and I haven't found any documentation on it.

Answer 2

You can use for in

  function printProperties(response, path){
      path = path || "";
     for (var prop in  response) {
         if(typeof response[prop] == 'object'){
             printProperties(response[prop], path + prop  + ".");
             continue;
          }

         console(path  + prop + " = " + response[prop]);
    }
}

​ jsfiddle

Answer 3

You can add it as a property to window and the use the DOM browser in firebug, it allows you to examine the entire object tree.

Answer 4

If you want to see it just by your self:

1. Open Chrome Inspector -> Web Console
2. console.log(response);
3. Enjoy, there you can view all properties recursively with details