How to recursively flatten a nested hash (object literal) in JavaScript.

gistfile1.js

// alternative approach for testing if value is an Object

(function() {

	'use strict';

	var hash = {
		level1a: 'l1a',
		level1b: 'l1b',
		level1c: {
			level2a: 'l2a',
			level2b: {
				level3a: 'l3a'
			},
			level2c: 'l2c'
		},
		level1d: 'l1d'
	};

	var x = 1,
	flat = {};

	function flatten(nested) {

		for (var key in nested) {

			if ( isObj(nested[key]) ) {
				console.log('nested ', nested[key]);
				flatten(nested[key]);
			} else {
				flat['prop' + x] = nested[key];
				x++;
			}

		}

		return flat;

	}

	function isObj(obj) {
		return obj === Object(obj);
	}

	console.log(flatten(hash));

}());

recursively-flatten-nested-hash.js

// How to recursively flatten a nested hash (object literal) in JavaScript.
(function() {
	'use strict';

	var nestedObj = {
			key1: 'k1',
			key2: 'k2',
			key3: {
				k3a: 'nested-k3a',
				k3b: 'nested-k3b'
			},
			key4: {
				k4a: {
					k4a1: 'doublenested-k4a'
				},
				k4b: 'nested-k4b'
			},
			key5: 'k5'
		},
		flat = {},
		x = 0;


	function flatten(obj) {

		//console.log('object being worked on: ', obj);

		for (var key in obj) {
			if (obj[key].constructor === Object) {
					//console.log('nested object found: ');
					flatten(obj[key]);
			} else {
				flat['prop-' + x] = obj[key];
				//console.log('flat is now: ', flat);

				x++;
			}
		} 
	}

	flatten(nestedObj);
	console.log('totally flat: ', flat);
}());