---
title: Change Question Visibility
product: Form Library
description: Make sure respondents only see questions relevant to them by using the visibleIf property that allows you to make questions visible or invisible based on preconfigured conditions. View a free demo for JavaScript to learn more.
framework: Angular
source: https://surveyjs.io/form-library/examples/implement-conditional-logic-to-change-question-visibility/angular
index: https://surveyjs.io/form-library/examples/overview.md
---

# Change Question Visibility (Angular)

SurveyJS Form Library allows you to show or hide any survey element based on certain criteria, for example, the response to the current question. With this capability, you can implement skip logic and branching in your survey.

To conditionally change the visibility of a survey page, panel, or question, specify its [`visibleIf`](/form-library/documentation/api-reference/question#visibleIf) property. It accepts a Boolean [expression](https://surveyjs.io/form-library/documentation/design-survey/conditional-logic#expressions). The survey element becomes visible when this expression evaluates to `true`. In this demo, a survey displays additional questions depending on the value you select in the NPS question. Refer to the following help topic for more information: [Conditional Visibility](/form-library/documentation/design-survey/conditional-logic#conditional-visibility).

## Files

### `src/app/components/json.ts`

```ts
export const json = {
  "title": "NPS Survey Question",
  "logo": "https://api.surveyjs.io/private/Surveys/files?name=bdf16c7e-fa1e-4e31-9d82-a6df1982c224",
  "logoWidth": "200px",
  "logoHeight": "80px",
  "logoFit": "cover",
  "logoPosition": "right",
  "elements": [
    {
      "type": "rating",
      "name": "nps-score",
      "title": "On a scale from 0 to 10, how likely are you to recommend us to a friend or colleague?",
      "rateMin": 0,
      "rateMax": 10,
      "minRateDescription": "Very unlikely",
      "maxRateDescription": "Very likely"
    },
    {
      "type": "comment",
      "name": "disappointing-experience",
      "visibleIf": "{nps-score} <= 5",
      "title": "How did we disappoint you and what can we do to make things right?",
      "maxLength": 300
    },
    {
      "type": "comment",
      "name": "improvements-required",
      "visibleIf": "{nps-score} >= 6",
      "title": "What can we do to make your experience more satisfying?",
      "maxLength": 300
    },
    {
      "type": "checkbox",
      "name": "promoter-features",
      "visibleIf": "{nps-score} >= 9",
      "title": "Which of the following features do you value the most?",
      "description": "Please select no more than three features.",
      "isRequired": true,
      "choices": [
        {
          "value": "performance",
          "text": "Performance"
        },
        {
          "value": "stability",
          "text": "Stability"
        },
        {
          "value": "ui",
          "text": "User interface"
        },
        {
          "value": "complete-functionality",
          "text": "Complete functionality"
        },
        {
          "value": "learning-materials",
          "text": "Learning materials (documentation, demos, code examples)"
        },
        {
          "value": "support",
          "text": "Quality support"
        }
      ],
      "showOtherItem": true,
      "otherPlaceholder": "Please specify...",
      "otherText": "Other features",
      "colCount": 2,
      "maxSelectedChoices": 3
    }
  ]
};
```

### `src/app/components/survey.component.css`

```css
/* You can add your custom CSS here. */
```

### `src/app/components/survey.component.html`

```html
<survey [model]="model" style="position: absolute; top: 0; left: 0; right: 0; bottom: 0; height:100%"></survey>
```

### `src/app/components/survey.component.ts`

```ts
import { Component, OnInit } from "@angular/core";
import { Model } from "survey-core";
import { json } from "./json";
import "./survey.component.css";
import "survey-core/survey-core.min.css";

@Component({
    // tslint:disable-next-line:component-selector
    selector: "component-survey",
    templateUrl: "./survey.component.html",
    styleUrls: ["./survey.component.css"]
})
export class SurveyComponent implements OnInit {
    model: Model;
    ngOnInit() {
        const survey = new Model(json);
        survey.onComplete.add((sender, options) => {
            console.log(JSON.stringify(sender.data, null, 3));
        });
        this.model = survey;
    }
}
```

### `src/app/components/theme.ts`

```ts
export const themeJson = {};
```

### `src/app/app.component.css`

```css

```

### `src/app/app.component.html`

```html
<component-survey></component-survey>
```

### `src/app/app.component.ts`

```ts
import { Component } from "@angular/core";

@Component({
    selector: "app-root",
    templateUrl: "./app.component.html",
    styleUrls: ["./app.component.css"]
})
export class AppComponent {
    title = "CodeSandbox";
}
```

### `src/app/app.module.ts`

```ts
import { BrowserModule } from "@angular/platform-browser";
import { NgModule } from "@angular/core";

import { AppComponent } from "./app.component";
import { SurveyModule } from "survey-angular-ui";
import { SurveyComponent } from "./components/survey.component";

@NgModule({
    declarations: [AppComponent, SurveyComponent],
    imports: [BrowserModule, SurveyModule],
    providers: [],
    bootstrap: [AppComponent]
})
export class AppModule { }
```

### `src/environments/environment.prod.ts`

```ts
export const environment = {
    production: true
};
```

### `src/environments/environment.ts`

```ts
// The file contents for the current environment will overwrite these during build.
// The build system defaults to the dev environment which uses `environment.ts`, but if you do
// `ng build --env=prod` then `environment.prod.ts` will be used instead.
// The list of which env maps to which file can be found in `.angular-cli.json`.

export const environment = {
    production: false
};
```

### `src/index.html`

```html
<app-root></app-root>
```

### `src/main.ts`

```ts
import { enableProdMode } from "@angular/core";
import { platformBrowserDynamic } from "@angular/platform-browser-dynamic";

import { AppModule } from "./app/app.module";
import { environment } from "./environments/environment";

if (environment.production) {
    enableProdMode();
}

platformBrowserDynamic()
    .bootstrapModule(AppModule)
    .catch(err => console.log(err));
```

### `src/polyfills.ts`

```ts
/**
 * This file includes polyfills needed by Angular and is loaded before the app.
 * You can add your own extra polyfills to this file.
 *
 * This file is divided into 2 sections:
 *   1. Browser polyfills. These are applied before loading ZoneJS and are sorted by browsers.
 *   2. Application imports. Files imported after ZoneJS that should be loaded before your main
 *      file.
 *
 * The current setup is for so-called "evergreen" browsers; the last versions of browsers that
 * automatically update themselves. This includes Safari >= 10, Chrome >= 55 (including Opera),
 * Edge >= 13 on the desktop, and iOS 10 and Chrome on mobile.
 *
 * Learn more in https://angular.io/docs/ts/latest/guide/browser-support.html
 */

/***************************************************************************************************
 * BROWSER POLYFILLS
 */

/** IE9, IE10 and IE11 requires all of the following polyfills. **/
// import 'core-js/es6/symbol';
// import 'core-js/es6/object';
// import 'core-js/es6/function';
// import 'core-js/es6/parse-int';
// import 'core-js/es6/parse-float';
// import 'core-js/es6/number';
// import 'core-js/es6/math';
// import 'core-js/es6/string';
// import 'core-js/es6/date';
// import 'core-js/es6/array';
// import 'core-js/es6/regexp';
// import 'core-js/es6/map';
// import 'core-js/es6/weak-map';
// import 'core-js/es6/set';

/** IE10 and IE11 requires the following for NgClass support on SVG elements */
// import 'classlist.js';  // Run `npm install classlist.js`.

/** IE10 and IE11 requires the following for the Reflect API. */
// import 'core-js/es6/reflect';

/** Evergreen browsers require these. **/
// Used for reflect-metadata in JIT. If you use AOT (and only Angular decorators), you can remove.
import "core-js/proposals/reflect-metadata";

/**
 * Required to support Web Animations `@angular/platform-browser/animations`.
 * Needed for: All but Chrome, Firefox and Opera. http://caniuse.com/#feat=web-animation
 **/
// import 'web-animations-js';  // Run `npm install web-animations-js`.

/***************************************************************************************************
 * Zone JS is required by default for Angular itself.
 */
import "zone.js/dist/zone"; // Included with Angular CLI.

/***************************************************************************************************
 * APPLICATION IMPORTS
 */
```

### `src/styles.css`

```css
/* You can add your custom CSS here. */
```

### `src/typings.d.ts`

```ts
/* SystemJS module definition */
declare var module: NodeModule;
interface NodeModule {
    id: string;
}
```

### `.angular-cli.json`

```json
{
  "apps": [
    {
      "root": "src",
      "outDir": "dist",
      "assets": [ "assets", "favicon.ico" ],
      "index": "index.html",
      "main": "main.ts",
      "polyfills": "polyfills.ts",
      "prefix": "app",
      "styles": [ "styles.css" ],
      "scripts": [ ],
      "environmentSource": "environments/environment.ts",
      "environments": {
        "dev": "environments/environment.ts",
        "prod": "environments/environment.prod.ts"
      }
    }
  ]
}
```

### `_tsconfig.json`

```json
{
  "compileOnSave": false,
  "compilerOptions": {
    "baseUrl": "./",
    "outDir": "./dist/out-tsc",
    "sourceMap": true,
    "declaration": false,
    "allowSyntheticDefaultImports": true,
    "downlevelIteration": true,
    "experimentalDecorators": true,
    "moduleResolution": "node",
    "importHelpers": true,
    "resolveJsonModule": true,
    "target": "es2015",
    "module": "es2020",
    "lib": [
      "es2018",
      "dom"
    ]
  }
}
```

### `package.json`

```json
{
  "name": "surveyjs-angular",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build --prod",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "14.1.1",
    "@angular/cdk": "14.1.1",
    "@angular/common": "14.1.1",
    "@angular/compiler": "14.1.1",
    "@angular/core": "14.1.1",
    "@angular/forms": "14.1.1",
    "@angular/platform-browser": "14.1.1",
    "@angular/platform-browser-dynamic": "14.1.1",
    "@angular/router": "14.1.1",
    "core-js": "3.6.4",
    "rxjs": "6.5.4",
    "survey-core": "latest",
    "survey-angular-ui": "latest",
    "tslib": "1.13.0",
    "zone.js": "0.11.7"
  },
  "devDependencies": {
    "@angular/cli": "1.6.6",
    "@angular/compiler-cli": "^5.2.0",
    "@angular/language-service": "^5.2.0",
    "@types/core-js": "0.9.46",
    "@types/jasmine": "~2.8.3",
    "@types/jasminewd2": "~2.0.2",
    "@types/node": "~6.0.60",
    "codelyzer": "^4.0.1",
    "jasmine-core": "~2.8.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~2.0.0",
    "karma-chrome-launcher": "~2.2.0",
    "karma-coverage-istanbul-reporter": "^1.2.1",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.2",
    "ts-node": "~4.1.0",
    "tslint": "~5.9.1",
    "typescript": "3.9.7"
  },
  "keywords": [ "angular", "surveyjs" ],
  "description": "SurveyJS-Angular example project"
}
```

## Other Frameworks

- [React](https://surveyjs.io/form-library/examples/implement-conditional-logic-to-change-question-visibility/reactjs.md)
- [Vue 3](https://surveyjs.io/form-library/examples/implement-conditional-logic-to-change-question-visibility/vue3js.md)
- [jQuery](https://surveyjs.io/form-library/examples/implement-conditional-logic-to-change-question-visibility/jquery.md)
- [Vanilla JS](https://surveyjs.io/form-library/examples/implement-conditional-logic-to-change-question-visibility/vanillajs.md)