How Angularjs Digest Cycle Works?

Digest cycle is what Angular JS triggers when a value in the model or view is changed.

The cycle sets off the watchers which then match the value of model and view to the newest value

. Digest cycle automatically runs when the code encounters a directive.

What is the difference between Digest () and apply ()?

$digest() gets called without any arguments. $apply() takes a function that it will execute before doing any updates

. The other difference is what they affect. $digest() will update the current scope and any child scopes.

What is AngularJS life cycle?

Life cycle, which has three phases:

bootstrap, compilation, and runtime

. Understanding the life cycle of an AngularJS application makes it easier to understand how to design and implement your code. The three phases of the life cycle of an AngularJS application happen each time a web page is loaded in the browser.

What is $watch and $Digest?

$watch() function which I will cover later in this text. At key points in your application AngularJS calls the $scope. $digest() function.

This function iterates through all watches and checks if any of the watched variables have changed

. If a watched variable has changed, a corresponding listener function is called.

Why we use $apply in AngularJS?

In AngularJS, $apply() function is used

to evaluate expressions outside of the AngularJS context

(browser DOM Events, XHR). Moreover, $apply has $digest under its hood, which is ultimately called whenever $apply() is called to update the data bindings.

What is a service in AngularJS?

In AngularJS, a service is

a function, or object, that is available for, and limited to, your AngularJS application

. AngularJS has about 30 built-in services. One of them is the $location service.

What is deep linking in AngularJS?

Deep linking is

the usage of the URL, which will take to specific page (content) directly without traversing application from home page

. It helps in getting indexed so that these links can be easily searchable by search engines like Google, Yahoo.. etc.

What is dirty checking in angular?

Dirty checking is a simple process that boils down to a very basic concept:

It checks whether a value has changed that hasn’t yet been synchronized across the app

. Our Angular app keeps track of the values of the current watches.

What is $dirty in AngularJS?

ng-dirty:

The ng-dirty class tells that the form has been made dirty (modified ) by the user

. It returns true if the user has modified the form. Return type: Return Boolean True if the form/input field is modified by the user else it returns False.

How Angular pipes work?

By default, pipes are defined as pure so that

Angular executes the pipe only when it detects a pure change to the input value

. A pure change is either a change to a primitive input value (such as String , Number , Boolean , or Symbol ), or a changed object reference (such as Date , Array , Function , or Object ).

Is AngularJS supports two-way binding True or false?

37) AngularJS application expressions are pure JavaScript expressions. 38)

AngularJS support two-way data binding

. Answer: A: True.

Which of the following is AngularJS modules life cycle phase?

Now that you understand the components involved in an AngularJS application, you need to understand what happens during the life cycle, which has three phases:

bootstrap, compilation, and runtime

.

What is dependency injection in AngularJS?

Dependency Injection (DI) is

a software design pattern that deals with how components get hold of their dependencies

. The AngularJS injector subsystem is in charge of creating components, resolving their dependencies, and providing them to other components as requested.

What is scope apply?

$apply() is

used to execute an expression in angular from outside of the angular framework

. (For example from browser DOM events, setTimeout, XHR or third party libraries). Because we are calling into the angular framework we need to perform proper scope life-cycle of exception handling, executing watches.

What is the angular equivalent to an AngularJS $Watch?

You can use

getter function or get accessor

to act as watch on angular 2.

What is second argument of Watch ()?

The angular JS $watch function is used to watch the scope object. The $watch keep an eye on the variable and as the value of the variable changes the angular JS $what runs a function. This function takes two arguments one is the new value and another parameter is

the old value

.

What features enables Spa feature in AngularJS?

• Its UI is fast and responsive. …
• IT contains more JavaScript code than actual HTML as compared to other applications.
• Dynamic data loading occurs from the server-side. …
• It allows to pre-load and cache all the app pages. …
• Applications written in AngularJS are cross-browser compliant.

What is the difference between factory and service in AngularJS?

The major difference between an AngularJS service and an AngularJS factory is that

a service is a constructor function and a factory is not

. That is why, in the case of a factory, we return an object literal instead of using this.

What are the filters in AngularJS?

What are AngularJS routes?

Routing in AngularJS is a method that

allows you to create Single Page Applications

. It enables you to create different URLs for different content in your web applications. AngularJS routing also helps to show multiple contents depending on which route is chosen. It is specified in the URL after the # sign.

What technique does AngularJS use for two way binding?

The

ng-model directive

provides a two-way binding between the model and the view.

What is Ng include in AngularJS?

AngularJS ng-include Directive

The ng-include directive

includes HTML from an external file

. The included content will be included as childnodes of the specified element. The value of the ng-include attribute can also be an expression, returning a filename.

What is one way binding in AngularJS?

One-way data binding in AngularJS means

binding data from Model to View

(Data flows from the scope/controller to the view). ‘ng-bind’ is an angular directive used for achieving one-way data binding.

What is pristine in Angular?

pristine:

This property returns true if the element’s contents have not been changed

. dirty: This property returns true if the element’s contents have been changed. untouched: This property returns true if the user has not visited the element.

What is dirty checking in hibernate?

Hibernate monitors all persistent objects. At the end of a unit of work, it knows which objects have been modified. Then it calls update statement on all updated objects. This

process of monitoring and updating only objects that have been changed

is called automatic dirty checking in hibernate.

What is dirty checking in react?

Dirty checking:

checks every node’s data at a regular interval to see if there have been any changes

. Dirty checking is not the optimal solution as it requires traversing every single node recursively to make sure its data is up to date.