JavaScript function to sort an array of objects in descending order by any one of the property present in all of the objects.

sortByProp.js

/*
	* Function : descBy(one of the property name of objects present in an array)
	* Usage    : arrayHoldingNames.sort(by(firstName));
	* ----------------------------------------------------------------------
	* Used to sort any array of objects in descending order by a property name 
	* of the obejcts inside that array.
	*/
	function descBy(propertyName) {
		return function(m, n) {
			if(typeof m === 'object' && typeof n === 'object') {
				var propertyValueM = m[propertyName];
				var propertyValueN = n[propertyName];

				if(propertyValueM === propertyValueN) return 0;
				if(typeof propetyValueM === typeof propertyVaueN) {
					return (propertyValueM < propertyValueN ? 1 : -1);
				}else{
					return (typeof propertyValueM < propertyValueN ? 1 : -1);
				}

			}else{
				throw {
					type : 'Error',
					message : 'Expected objects got something else'
				};
			}
		}
	}