Angular Interview Questions & Answers

1              What is Angular Framework?

2              What is the difference between AngularJS and Angular?

3              What is TypeScript?

4              Write a pictorial diagram of Angular architecture?

5              What are the key components of Angular?

6              What are directives?

7              What are components?

8              What are the differences between Component and Directive?

9              What is a template?

10           What is a module?

11           What are lifecycle hooks available?

12           What is a data binding?

13           What is metadata?

14           What is Angular CLI?

15           What is the difference between constructor and ngOnInit?

16           What is a service

17           What is dependency injection in Angular?

18           How is Dependency Hierarchy formed?

19           What is the purpose of async pipe?

20           What is the option to choose between inline and external template file?

21           What is the purpose of *ngFor directive?

22           What is the purpose of ngIf directive?

23           What happens if you use script tag inside template?

24           What is interpolation?

25           What are template expressions?

26           What are template statements?

27           How do you categorize data binding types?

28           What are pipes?

29           What is a parameterized pipe?

30           How do you chain pipes?

31           What is a custom pipe?

32           Give an example of custom pipe?

33           What is the difference between pure and impure pipe?

34           What is a bootstrapping module?

35           What are observables?

36           What is HttpClient and its benefits?

37           Explain on how to use HttpClient with an example?

38           How can you read full response?

39           How do you perform Error handling?

40           What is RxJS?

41           What is subscribing?

42           What is an observable?

43           What is an observer?

44           What is the difference between promise and observable?

45           What is multicasting?

46           How do you perform error handling in observables?

47           What is the short hand notation for subscribe method?

48           What are the utility functions provided by RxJS?

49           What are observable creation functions?

50           What will happen if you do not supply handler for observer?

51           What are angular elements?

52           What is the browser support of Angular Elements?

53           What are custom elements?

54           Do I need to bootstrap custom elements?

55           Explain how custom elements works internally?

56           How to transfer components to custom elements?

57           What are the mapping rules between Angular component and custom element?

58           How do you define typings for custom elements?

59           What are dynamic components?

60           What are the various kinds of directives?

61           How do you create directives using CLI?

62           Give an example for attribute directives?

63           What is Angular Router?

64           What is the purpose of base href tag?

65           What are the router imports?

66           What is router outlet?

67           What are router links?

68           What are active router links?

69           What is router state?

70           What are router events?

71           What is activated route?

72           How do you define routes?

73           What is the purpose of Wildcard route?

74           Do I need a Routing Module always?

75           What is Angular Universal?

76           What are different types of compilation in Angular?

77           What is JIT?

78           What is AOT?

79           Why do we need compilation process?

80           What are the advantages with AOT?

81           What are the ways to control AOT compilation?

82           What are the restrictions of metadata?

83           What are the three phases of AOT?

84           Can I use arrow functions in AOT?

85           What is the purpose of metadata json files?

86           Can I use any javascript feature for expression syntax in AOT?

87           What is folding?

88           What are macros?

89           Give an example of few metadata errors?

90           What is metadata rewriting?

91           How do you provide configuration inheritance?

92           How do you specify angular template compiler options?

93           How do you enable binding expression validation?

94           What is the purpose of any type cast function?

95           What is Non null type assertion operator?

96           What is type narrowing?

97           How do you describe various dependencies in angular application?

98           What is zone?

99           What is the purpose of common module?

100         What is codelyzer?

101         What is angular animation?

102         What are the steps to use animation module?

103         What is State function?

104         What is Style function?

105         What is the purpose of animate function?

106         What is transition function?

107         How to inject the dynamic script in angular?

108         What is a service worker and its role in Angular?

109         What are the design goals of service workers?

110         What are the differences between AngularJS and Angular with respect to dependency injection?

111         What is Angular Ivy?

112         What are the features included in ivy preview?

113         Can I use AOT compilation with Ivy?

114         What is Angular Language Service?

115         How do you install angular language service in the project?

116         Is there any editor support for Angular Language Service?

117         Explain the features provided by Angular Language Service?

118         How do you add web workers in your application?

119         What are the limitations with web workers?

120         What is Angular CLI Builder?

121         What is a builder?

122         How do you invoke a builder?

123         How do you create app shell in Angular?

124         What are the case types in Angular?

125         What are the class decorators in Angular?

126         What are class field decorators?

127         What is declarable in Angular?

128         What are the restrictions on declarable classes?

129         What is a DI token?

130         What is Angular DSL?

131         What is an rxjs Subject?

132         What is Bazel tool?

133         What are the advantages of Bazel tool?

134         How do you use Bazel with Angular CLI?

135         How do you run Bazel directly?

136         What is platform in Angular?

137         What happens if I import the same module twice?

138         How do you select an element with in a component template?

139         How do you detect route change in Angular?

140         How do you pass headers for HTTP client?

141         What is the purpose of differential loading in CLI?

142         Is Angular supports dynamic imports?

143         What is lazy loading?

144         What are workspace APIs?

145         How do you upgrade angular version?

146         What is Angular Material?

147         How do you upgrade location service of angularjs?

148         What is NgUpgrade?

149         How do you test Angular application using CLI?

150         How to use polyfills in Angular application?

151         What are the ways to trigger change detection in Angular?

152         What are the differences of various versions of Angular?

153         What are the security principles in angular?

154         What is the reason to deprecate Web Tracing Framework?

155         What is the reason to deprecate web worker packages?

156         How do you find angular CLI version?

157         What is the browser support for Angular?

158         What is schematic

159         What is rule in Schematics?

160         What is Schematics CLI?

161         What are the best practices for security in angular?

162         What is Angular security model for preventing XSS attacks?

163         What is the role of template compiler for prevention of XSS attacks?

164         What are the various security contexts in Angular?

165         What is Sanitization? Is angular supports it?

166         What is the purpose of innerHTML?

167         What is the difference between interpolated content and innerHTML?

168         How do you prevent automatic sanitization?

169         Is safe to use direct DOM API methods in terms of security?

170         What is DOM sanitizer?

171         How do you support server side XSS protection in Angular application?

172         Is angular prevents http level vulnerabilities?

173         What are Http Interceptors?

174         What are the applications of HTTP interceptors?

175         Is multiple interceptors supported in Angular?

176         How can I use interceptor for an entire application?

177         How does Angular simplifies Internationalization?

178         How do you manually register locale data?

179         What are the four phases of template translation?

180         What is the purpose of i18n attribute?

181         What is the purpose of custom id?

182         What happens if the custom id is not unique?

183         Can I translate text without creating an element?

184         How can I translate attribute?

185         List down the pluralization categories?

186         What is select ICU expression?

187         How do you report missing translations?

188         How do you provide build configuration for multiple locales?

189         What is an angular library?

190         What is AOT compiler?

191         How do you select an element in component template?

192         What is TestBed?

193         What is protractor?

194         What is collection?

195         How do you create schematics for libraries?

196         How do you use jquery in Angular?

197         What is the reason for No provider for HTTP exception?

198         What is router state?

199         How can I use SASS in angular project?

200         What is the purpose of hidden property?

201         What is the difference between ngIf and hidden property?

202         What is slice pipe?

203         What is index property in ngFor directive?

204         What is the purpose of ngFor trackBy?

205         What is the purpose of ngSwitch directive?

206         Is it possible to do aliasing for inputs and outputs?

207         What is safe navigation operator?

208         Is any special configuration required for Angular9?

209         What are type safe TestBed API changes in Angular9?

210         Is mandatory to pass static flag for ViewChild?

211         What are the list of template expression operators?

212         What is the precedence between pipe and ternary operators?

213         What is an entry component?

214         What is a bootstrapped component?

215         How do you manually bootstrap an application?

216         Is it necessary for bootstrapped component to be entry component?

217         What is a routed entry component?

218         Why is not necessary to use entryComponents array every time?

219         Do I still need to use entryComponents array in Angular9?

220         Is it all components generated in production build?

221         What is Angular compiler?

222         What is the role of ngModule metadata in compilation process?

223         How does angular finds components, directives and pipes?

224         Give few examples for NgModules?

225         What are feature modules?

226         What are the imported modules in CLI generated feature modules?

227         What are the differences between ngmodule and javascript module?

228         What are the possible errors with declarations?

229         What are the steps to use declaration elements?

230         What happens if browserModule used in feature module?

231         What are the types of feature modules?

232         What is a provider?

233         What is the recommendation for provider scope?

234         How do you restrict provider scope to a module?

235         How do you provide a singleton service?

236         What are the different ways to remove duplicate service registration?

237         How does forRoot method helpful to avoid duplicate router instances?

238         What is a shared module?

239         Can I share services using modules?

240         How do you get current direction for locales??

241         What is ngcc?

242         What classes should not be added to declarations?

243         Wat is ngzone?

244         What is NoopZone?

245         How do you create displayBlock components?

246         What are the possible data change scenarios for change detection?

247         What is a zone context?

248         What are the lifecycle hooks of a zone?

249         Which are the methods of NgZone used to control change detection?

250         How do you change the settings of zonejs?

251         How do you trigger an animation?

252         How do you configure injectors with providers at different levels?

253         Is it mandatory to use injectable on every service class?

254         What is an optional dependency?

255         What are the types of injector hierarchies?

256         What are reactive forms?

257         What are dynamic forms?

258         What are template driven forms?

259         What are the differences between reactive forms and template driven forms?

260         What are the different ways to group form controls?

261         How do you update specific properties of a form model?

262         What is the purpose of FormBuilder?

263         How do you verify the model changes in forms?

264         What are the state CSS classes provided by ngModel?

265         How do you reset the form?

266         What are the types of validator functions?

267         Can you give an example of built-in validators?

268         How do you optimize the performance of async validators?

269         How to set ngFor and ngIf on the same element?

270         What is host property in css?

271         How do you get the current route?

272         What is Component Test Harnesses?

273         What is the benefit of Automatic Inlining of Fonts?

274         What is content projection?

275         What is ng-content and its purpose?