var classes = {};

var cmdb = new GlideRecord('cmdb_ci');
cmdb.addActiveQuery();
cmdb.query();

while(cmdb.next()) {

	if(typeof classes[cmdb.sys_class_name.toString()] != 'undefined') {
		classes[cmdb.sys_class_name.toString()].count++
	}
	else {
		classes[cmdb.sys_class_name.toString()] = { name: cmdb.sys_class_name.toString(), count: 1 };
	}

}

gs.print(JSON.stringify(classes));