function main(projectId) {
  // [START compute_instances_list_all]
  /**
   * TODO(developer): Uncomment and replace these variables before running the sample.
   */
  // const projectId = 'YOUR_PROJECT_ID';

  const compute = require('@google-cloud/compute');

  // List all instances in the specified project.
  async function listAllInstances() {
    const instancesClient = new compute.InstancesClient();

    //Use the `maxResults` parameter to limit the number of results that the API returns per response page.
    const aggListRequest = instancesClient.aggregatedListAsync({
      project: projectId,
      maxResults: 5,
    });

    console.log('Instances found:');

    // Despite using the `maxResults` parameter, you don't need to handle the pagination
    // yourself. The returned object handles pagination automatically,
    // requesting next pages as you iterate over the results.
    for await (const [zone, instancesObject] of aggListRequest) {
      const instances = instancesObject.instances;

      if (instances && instances.length > 0) {
        console.log(` ${zone}`);
        for (const instance of instances) {
          console.log(` - ${instance.name} (${instance.machineType})`);
        }
      }
    }
  }

  listAllInstances();
  // [END compute_instances_list_all]
}
Gets all instances present in a project, grouped by their zone.

@param {string} projectId - ID or number of the project you want to use.