How can I check if a JSON is empty in NodeJS?

Question

I have a function that checks to see whether or not a request has any queries, and does different actions based off that. Currently, I have if(query) do this else something else. However, it seems that when there is no query data, I end up with a {} JSON object. As such, I need to replace if(query) with if(query.isEmpty()) or something of that sort. Can anybody explain how I could go about doing this in NodeJS? Does the V8 JSON object have any functionality of this sort?

Answer 1

You can use either of these functions:

// This should work in node.js and other ES5 compliant implementations. function isEmptyObject(obj) {   return !Object.keys(obj).length; }  // This should work both there and elsewhere. function isEmptyObject(obj) {   for (var key in obj) {     if (Object.prototype.hasOwnProperty.call(obj, key)) {       return false;     }   }   return true; } 

Example usage:

if (isEmptyObject(query)) {   // There are no queries. } else {   // There is at least one query,   // or at least the query object is not empty. } 

Answer 2

You can use this:

var isEmpty = function(obj) {   return Object.keys(obj).length === 0; } 

or this:

function isEmpty(obj) {   return !Object.keys(obj).length > 0; } 

You can also use this:

function isEmpty(obj) {   for(var prop in obj) {     if(obj.hasOwnProperty(prop))       return false;   }    return true; } 

If using underscore or jQuery, you can use their isEmpty or isEmptyObject calls.