# Javascript: How to test if response JSON array is empty

I'm getting back the following JSON:

{"array":[],"object":null,"bool":false}


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

$.ajax({ type: "GET", url: "/ajax/rest/siteService/list", dataType: "json", success: function (response) { var siteArray = response.array; // Handle the case where the user may not belong to any groups if (siteArray === null || siteArray=== undefined || siteArray=== '' || siteArray.length === 0) { window.alert('hi'); } } });  But the alert is not firing. :[ ## Answers Use$.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
}