Javascript: How to test if response JSON array is empty

I'm getting back the following JSON:


And I'm testing it with the following, seemingly exhaustive, if statement:

        type: "GET",
        url: "/ajax/rest/siteService/list",
        dataType: "json",
        success: function (response) {
            var siteArray = response.array;

            // Handle the case where the user may not belong to any groups
            if (siteArray === null || siteArray=== undefined || siteArray=== '' || siteArray.length === 0) {

But the alert is not firing. :[


Use $.isArray() to check whether an object is an array. Then you can check the truthness of the length property to see whether it is empty.

if( !$.isArray(siteArray) ||  !siteArray.length ) {
    //handler either not an array or empty array

Need Your Help

JSF 2 - How can I add an Ajax listener method to composite component interface?

java ajax jsf-2 listener composite-component

I have a JSF 2 composite component that employs some Ajax behavior. I want to add a listener method to the <f:ajax> tag inside my composite component, but the listener method should be provid...