Impelsys Senior Angular Developer Interview Questions and Answers

ng-template, ng-content, and ng-container are Angular structural directives used for template rendering and content projection.

• ng-template is used to define a template that can be rendered conditionally or multiple times.

• ng-content is used for content projection, allowing the insertion of content from a parent component into a child component.

• ng-container is a grouping element that doesn't interfere with styles or layout, often used to wrap multiple elements for structural pu...read more

Custom pipes in Angular are used to transform data in templates.

• Custom pipes are created using the @Pipe decorator in Angular.

• To use a custom pipe in HTML, you need to include it in the declarations array of the NgModule.

• You can pass parameters to custom pipes in HTML using the pipe symbol (|).

• Example: {{ value | customPipe:param1:param2 }}

Handle errors in fetching API calls by implementing error handling mechanisms.

• Use try-catch blocks to catch errors during API calls

• Implement error handling logic in the catch block to handle different types of errors

• Display user-friendly error messages to inform users about the issue

• Use HTTP status codes to identify the type of error (e.g. 404 for not found)

• Implement retry mechanisms for temporary network issues

ForkJoin is an operator in Angular that allows for parallel execution of multiple observables.

• ForkJoin combines the values from multiple observables and emits them as an array when all observables complete.

• It waits for all observables to complete and then emits the combined result.

• Example: forkJoin([observable1, observable2]).subscribe(result => console.log(result));

Arrow functions are concise and do not bind their own 'this' value, while regular functions have their own 'this' value and can be used as constructors.

• Arrow functions have a more concise syntax compared to regular functions.

• Arrow functions do not have their own 'this' value, they inherit it from the parent scope.

• Regular functions have their own 'this' value, which can be useful for object-oriented programming and constructor functions.

Wildcard routes in Angular allow for handling unknown routes and redirecting to a default route.

• Wildcard route is denoted by '**' in the route configuration.

• It is typically used at the end of the route configuration to handle unknown routes.

• Example: { path: '**', redirectTo: '/404' }

ES6 features are modern JavaScript enhancements that improve code readability and efficiency.

• Arrow functions for concise syntax: const add = (a, b) => a + b;

• Let and const for block-scoped variables: let x = 5; const y = 10;

• Template literals for string interpolation: const name = 'John'; console.log(`Hello, ${name}!`);

• Destructuring assignment for easily extracting values from arrays or objects: const { firstName, lastName } = person;

• Spread syntax for merging arrays or objects:...read more

Shallow copy only copies the references of nested objects, while deep copy creates new copies of nested objects.

• Shallow copy creates a new object but does not create copies of nested objects.

• Deep copy creates a new object and also creates copies of nested objects.

• Shallow copy is faster and more memory efficient, but changes to nested objects affect both original and copied objects.

• Deep copy is slower and consumes more memory, but changes to nested objects do not affect the or...read more