HCLTech Consultant Interview Questions, Process, and Tips

Template Driven vs Reactive Forms

• Template Driven Forms are easy to use and require less code

• Reactive Forms are more flexible and provide better control over form validation

• Template Driven Forms are suitable for simple forms while Reactive Forms are better for complex forms

• Reactive Forms allow for dynamic form creation and modification

• Template Driven Forms are based on directives while Reactive Forms are based on reacti...read more

Angular forms have inbuilt and custom validations to ensure data accuracy.

• Inbuilt validations include required, minlength, maxlength, pattern, and email.

• Custom validations can be created using Validators class and adding them to the form controls.

• Validation messages can be displayed using ngIf and ngMessages directives.

• Form level validations can be implemented using FormGroup and FormBuilder.

• Validators can also be used

Observables are streams of data that can be subscribed to, while Promises are one-time operations that return a single value.

• Observables can emit multiple values over time, while Promises only emit a single value.

• Observables can be cancelled, while Promises cannot.

• Observables are lazy, meaning they only execute when subscribed to, while Promises execute immediately.

• Observables have operators that can transform, filter,...read more

Error handling in observables is crucial for ensuring smooth functioning of the application.

• Use catchError operator to handle errors in observables

• Throw custom errors using throwError operator

• Use retry operator to retry failed requests

• Use finalize operator to perform cleanup operations

• Avoid using try-catch blocks in observables

JIT compiles code at runtime while AOT compiles code before runtime.

• JIT stands for Just-In-Time compilation and compiles code at runtime.

• AOT stands for Ahead-Of-Time compilation and compiles code before runtime.

• JIT can result in slower startup times but faster execution times.

• AOT can result in faster startup times but slower execution times.

• Examples of JIT languages include Java and JavaScript.

• Examples of AOT languages