unique-id demo

helpers.unique-id\.js

import { helper } from '@ember/component/helper';
import { guidFor } from '@ember/object/internals';

export default helper(function uniqueId() {
  return guidFor({});
});

templates.application\.hbs

<h1><code>unique-id</code> demo</h1>
<ul>
{{#each (array 1 2 3 4 5) as |_|}}
  {{#let (unique-id) as |id|}}
    <li>{{id}}</li>
  {{/let}}
{{/each}}
</ul>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0"
  }
}