<!DOCTYPE html> <html> <head> <title></title> <meta charset="utf-8"> <meta name="viewport" content="width=device-width,initial-scale=1"> <script src="https://code.jquery.com/jquery-3.4.1.min.js"></script> <style> </style> </head> <body> <div id="result"></div> <script> $(function(){ var arr=[]; var b=$.isPlainObject({}); arr.push('$.isPlainObject({}): ' + b); b=$.isPlainObject(new Object()); arr.push('$.isPlainObject(new Object()): ' + b); b=$.isPlainObject("Hello World!"); arr.push('$.isPlainObject("Hello World!"): ' + b); b=$.isPlainObject($); arr.push('$.isPlainObject($): ' + b); b=$.isPlainObject(document.location); arr.push('$.isPlainObject(document.location): ' + b); $("#result").html(arr.join("<br>")); }); </script> </body> </html>