Question

I’m working with some images from the Flickr API using jQuery, and looping through the result set.

This works:

$.getJSON(apiCall, function(data) {
    //LOOP THROUGH DATA
    $.each(data.photos.photo, function(i, photo) {
        // do stuff
    });
});

but when I added a check to make sure that the photos object was populated, the length property is undefined.

$.getJSON(apiCall, function(data) {

    console.log(data.photos.length); // returns undefined

    if(data.photos.length >= 1){
        //LOOP THROUGH DATA
        $.each(data.photos.photo, function(i, photo) {
            // do stuff
        });
    } else {
        // do other stuff
    }
});

What is the proper way to determine whether the photos object is populated?

EDIT: sample of json data returned:

{"photos":{"page":1, "pages":100172, "perpage":50, "total":"5008581", "photo":[{"id":"8077408556", "owner":"75972124@N08", "secret":"ede5a49ab5", "server":"8323", "farm":9, "title":"zara 2", "ispublic":1, "isfriend":0, "isfamily":0}. . .

Yes, it is possible to simply test if photos.total >= 1 but I’m curious about the length property.

Answer 1

Try

$.getJSON(apiCall, function(data) {

    console.log(data.photos.photo.length); // returns undefined

    if(data.photos.photo.length >= 1){
        //LOOP THROUGH DATA
        $.each(data.photos.photo, function(i, photo) {
            // do stuff
        });
    } else {
        // do other stuff
    }
});

To get the length, you need to use data.photos.photo