Blockly renders to ECMAScript 5.1 which isn’t going to be much help. But from the reference docs above you’ll see that the ECMAScript 2021 equivalent would be something like
Calling getItem(...) returns an Item object with the following properties:
Item : object
.type ⇒ String
.name ⇒ String
.label ⇒ String
.history ⇒ ItemHistory
.state ⇒ String
.rawState ⇒ HostState
.members ⇒ Array.<Item>
.descendents ⇒ Array.<Item>
.isUninitialized ⇒ Boolean
.groupNames ⇒ Array.<String>
.tags ⇒ Array.<String>
.getMetadataValue(namespace) ⇒ String
.updateMetadataValue(namespace, value) ⇒ String
.upsertMetadataValue(namespace, value) ⇒ Boolean
.updateMetadataValues(namespaceToValues)
.sendCommand(value)
.sendCommandIfDifferent(value) ⇒ Boolean
.postUpdate(value)
.addGroups(…groupNamesOrItems)
.removeGroups(…groupNamesOrItems)
.addTags(…tagNames)
.removeTags(…tagNames)
This means:
The members of your House group are returned as an Array (you can also see this in your log message with the brackets: []).
To log the label of each group member (as an example), which is an element of the Array, there are some possibilities:
// the array with the members of the „House“ group
var members = items.getItem('House').members;
// this logs the label of each member to a new line
members.forEach((item) => console.info(item.label));
// this uses the map function of Array to generate a new array with the names of the group members
// and joins the names into a single string
console.info(members.map((item) => item.name).join(', '));