Get custom JS variables of a web page

custom_variables.js

/*
First version
*/

function getCustomVariables(){
	let page_variables = Object.keys(window); // current page's variables
	let default_variables = Object.keys(document.head.appendChild(document.createElement('iframe')).contentWindow); // empty DOM's variables
	let custom_variables = page_variables.filter(variable => default_variables.indexOf(variable) == -1); // comparison
	return custom_variables;
}

getCustomVariables().forEach(variable => console.log(variable, window[variable]));

/*
Second version
Sorted result
*/

function getCustomVariables(){
	let page_variables = Object.keys(window); // current page's variables
	let default_variables = Object.keys(document.head.appendChild(document.createElement('iframe')).contentWindow); // empty DOM's variables
	let custom_variables = page_variables.filter(variable => default_variables.indexOf(variable) == -1); // comparison
	let sorted_result = {};
	custom_variables.forEach(v => {
		if(sorted_result[typeof(window.v)] === undefined)
			sorted_result[typeof(window.v)] = [];
		sorted_result[typeof(window.v)].push(v);
	});
	return sorted_result;
}

console.log(getCustomVariables());