Javascript: How Do I Access Values In Nested Objects If I Don’t Know The Object’s Key?

If I have a Javascript object, parsed from JSON, that’s nested three deep, and I don’t know the key for the middle one, how to I access it and its contents? The actual data I�

Solution 1:

Based on the sample you posted, the files property is not an array, so can't be accessed by an indexer. This is a case where you would use a for-in loop rather than a regular for loop.

for(var p in responseObj[0].files) {                 
  if ( responseObj[0].files.hasOwnProperty (p) ) {   
    p; // p is your unknown property name
    responseObj[0].files[p]; // is the object which you can use to access // its own properties (filename, type, etc)           
  }                                                                                                           
}

The hasOwnProperty check will skip the automatic members like toString and only return those manually defined on the object.

Solution 2:

If you want to iterate over them, do something like

for (var fileID in responseObj[0].files) {
    var file = responseObj[0].files[fileID];
    var filename = file.filename;
}