5 ways to determine whether an object is an empty object in JS

1. Convert the json object into a json string, and then determine whether the string is "{}"

var data = {};
var b = (JSON.stringify(data) == "{}");
alert(b);//true

2. for in loop judgment

var obj = {};
var b = function() {
    for(var key in obj) {
        return false;
    }
    return true;
}
alert(b());//true

3. jQuery's isEmptyObject method

This method is a jQuery encapsulation of the 2 method (for in), and it needs to rely on jQuery when used.

var data = {};
var b = $.isEmptyObject(data);
alert(b);//true

4.Object.getOwnPropertyNames() method

This method uses the getOwnPropertyNames method of the Object object to obtain the property names in the object, store them in an array, and return the array object. We can determine whether this object is empty by judging the length of the array. Note: This method is not compatible with IE8 and has not been tested on other browsers.

var data = {};
var arr = Object.getOwnPropertyNames(data);
alert(arr.length == 0); //true

5. Use ES6's Object.keys() method

Similar to method 4, it is a new method of ES6, and the return value is also an array of attribute names in the object

var data = {};
var arr = Object.keys(data);
alert(arr.length == 0); //true

This concludes this article about 5 ways to use JS to determine whether an object is empty. For more information about how to use JS to determine whether an object is empty, please search previous articles on 123WORDPRESS.COM or continue browsing the following related articles. I hope you will support 123WORDPRESS.COM in the future!