Question 1

What is Module in ServiceNow?

Accepted Answer

`angular.module('app', ['ngRoute'])` declares an app and its dependencies. Second arg is required on creation, omitted on lookup.

Question 2

What is Controller in ServiceNow?

Accepted Answer

Should be thin: wire data from services to $scope, expose handlers. Keep business logic in services so it's testable.

Question 3

What is Two-way binding in ServiceNow?

Accepted Answer

ng-model writes form input to $scope; Angular re-renders the DOM when scope changes during a $digest. Costly if abused.

Question 4

What is Expression in ServiceNow?

Accepted Answer

`{{user.name}}` and `ng-click='save()'` are expressions. No control flow, no `new`, no comparisons against window globals.

Question 5

What is ng-app in ServiceNow?

Accepted Answer

Place on <html> or a sub-element. `ng-app="myApp"` auto-bootstraps after DOMContentLoaded; omit value to use the implicit root module.

Question 6

What is controllerAs in ServiceNow?

Accepted Answer

`ng-controller="Ctrl as vm"` exposes the controller instance as `vm` — avoids primitives-on-$scope and the dot-rule trap.

Question 7

What is Filter in ServiceNow?

Accepted Answer

`{{ price | currency }}`. Built-ins: date, filter, orderBy, json, uppercase. Custom: app.filter('foo', fn).

Question 8

What is ng-repeat in ServiceNow?

Accepted Answer

Use `track by item.id` to avoid re-rendering everything when the underlying array is replaced.

Question 9

What is ng-if vs ng-show in ServiceNow?

Accepted Answer

ng-if creates a new scope and removes the subtree (and its watchers). ng-show just flips CSS.

Question 10

What is ng-model in ServiceNow?

Accepted Answer

Adds a NgModelController with $parsers/$formatters/$validators pipeline.

Question 11

What is ng-class in ServiceNow?

Accepted Answer

Object form: `ng-class="{active: isOn, 'is-error': hasErr}"`. Re-evaluated each digest — keep expressions cheap.

Question 12

What is ng-bind / one-time :: in ServiceNow?

Accepted Answer

`ng-bind="name"` evaluates after compilation. `{{::name}}` deregisters its watcher once value is defined.

Question 13

What is $rootScope in ServiceNow?

Accepted Answer

Singleton scope. Useful for cross-cutting events ($broadcast) but easy to abuse — prefer services for shared state.

Question 14

What is angular.bootstrap in ServiceNow?

Accepted Answer

`angular.bootstrap(document, ['myApp'])`. Use when ng-app can't run (multiple apps on one page, async load).

Question 15

What is Strict DI (ng-strict-di) in ServiceNow?

Accepted Answer

Add `ng-strict-di` next to `ng-app` to crash if any service uses implicit (param-name) DI — catches minification bugs early.

🅰️ CORE CONCEPTS

Term Glossary