TCS Interview Questions and Answers

Change detection strategy in Angular is a mechanism used to detect changes in the application state and update the view accordingly.

• Angular uses Zone.js for change detection by default

• Change detection can be triggered manually using ChangeDetectorRef

• Optimizing change detection using OnPush strategy

Closure is a function that captures the variables from its surrounding scope, even after the surrounding function has finished executing.

• Closure allows a function to access and manipulate variables from its outer scope.

• It maintains a reference to its outer scope, even after the outer function has returned.

• Closure is commonly used in event handlers and callbacks.

var is function scoped, let is block scoped, const is block scoped and cannot be reassigned.

• var is function scoped, let is block scoped, const is block scoped and cannot be reassigned

• var can be redeclared and updated, let can be updated but not redeclared, const cannot be redeclared or updated

• Example: var x = 10; let y = 20; const z = 30;

Rxjs operators are used for handling asynchronous operations in reactive programming.

• Map operator: transforms the items emitted by an Observable

• Filter operator: emits only those items from an Observable that pass a specified condition

• Merge operator: combines multiple Observables into one by merging their emissions

• SwitchMap operator: switches to a new Observable each time it is emitted

• DebounceTime operator: emits a value from the source Observable only after a specified time h...read more

To find the next highest number, sort the numbers in ascending order and find the number immediately greater than the given number.

• Sort the numbers in ascending order

• Find the number immediately greater than the given number

• Return the next highest number