How do you do ng-options?

The ng-options directive fills a <select> element with <options>. The ng-options directive uses an array to fill the dropdown list. In many cases it would be easier to use the ng-repeat directive, but you have more flexibility when using the ng-options directive.

Table of Contents

What is ngOptions?

The ngOptions attribute can be used to dynamically generate a list of <option> elements for the <select> element using the array or object obtained by evaluating the ngOptions comprehension expression.

How do I filter with Ng-options?

In AngularJS when you are using ng-options, you can filter out the options by calling a custom function you have in the controller. Let’s say you have following set of employees and when you display all these employees inside HTML select using ng-options, you can see all the employees in a dropdown.

What is difference between ng-repeat and Ng-options?

ng-options is the directive which is designed specifically to populate the items of a dropdown list. One major advantage using ng-options for the dropdown is, it allows us to pass the selected value to be an object. Whereas, using ng-repeat the selected value can only be string.

How do I set default value in ng options?

Use ng-init to set default value for ng-options .

What is ngInit?

The ngInit directive allows you to evaluate an expression in the current scope. This directive can be abused to add unnecessary amounts of logic into your templates. There are only a few appropriate uses of ngInit : aliasing special properties of ngRepeat , as seen in the demo below.

Can we use filter in NG model?

You can’t use a filter in ng-model as it needs the expression to be assignable (i.e. it must be able to appear on the left hand side of an assignment).

What is Ng repeat?

Definition and Usage

The ng-repeat directive repeats a set of HTML, a given number of times. The set of HTML will be repeated once per item in a collection. The collection must be an array or an object. Note: Each instance of the repetition is given its own scope, which consist of the current item.

How do I set the default option in select?

The default value of the select element can be set by using the ‘selected’ attribute on the required option. This is a boolean attribute. The option that is having the ‘selected’ attribute will be displayed by default on the dropdown list.

Why ng-init is used?

The ng-init Directive is used to initialize AngularJS Application data. It defines the initial value for an AngularJS application and assigns values to the variables. The ng-init directive defines initial values and variables for an AngularJS application.

When Ng-INIT is called?

In Angular 1. x, ngInit is called when template is re-rendered. In other words “ng-init” is called, when I take turns back to a page. In Angular2, there is no “ng-init” but we can create a ways like this using the directive and ngOnInit class.

Can ngModel have multiple values?

You cannot, but there are some workarounds.

What is difference between ngModel and ngModel?

The answer is: (ngModel) causes a 1-way data-binding, whereas [(ngModel)] ensures a two-way data binding.

How do I create an index in NG-repeat?

Note: The $index variable is used to get the Index of the Row created by ng-repeat directive. Each row of the HTML Table consists of a Button which has been assigned ng-click directive. The $index variable is passed as parameter to the GetRowIndex function.

How do you pass an index in NG-repeat?

Linked

Using ng-repeat using different index values.
using ng-repeat inside another ng-repeat.
AngularJS – How to get two indexes.
AngularJS – original index of an object within filtered ng-repeat.
ng-repeat based on <select> option.
angular templating: ng-repeat comma-separated links.

How do I get a dropdown selected value?

Get Dropdown Selected Value using JavaScript

function GetMaster1Details()
{
var value = document. getElementById(“<%=ddlMaster1. ClientID%>”);
var getvalue = value. options[value. selectedIndex]. value;
var gettext = value. options[value. selectedIndex].
alert(“value:-” +” “+ getvalue + ” “+ “Text:-” +” “+ gettext);
}

What is NG model?

The ngModel directive is a directive that is used to bind the values of the HTML controls (input, select, and textarea) or any custom form controls, and stores the required user value in a variable and we can use that variable whenever we require that value. It also is used during form validations.

Is ngOnInit required?

ngOnInit: OnInit is a life cycle widget called Angular to show that Angular is made to create a component. We have to import OnInit like this to use it (actually using OnInit is not mandatory but it is considered good).

Which runs first constructor or ngOnInit?

Conclusion. Constructor initialize class members. ngOnInit() is a place to put the code that we need to execute at very first as soon as the class is instantiated.

What is [( ngModel )]?

How do I store multiple values in ngModel?

Basically bind your ng-model to selectedProject[$index] . This would bind the selected value to element in the array. This array can be later used to submit data. So $scope.

What is diff between ngModel and [( ngModel )]?

[ngModel] evaluates the code and generates an output (without two-way binding). [(ngModel)] evaluates the code and generates an output and also enables two-way binding.

What can I use instead of NG-repeat?

You can consider using transclusion inside a custom directive, to achieve the behavior you are looking for without using ng-repeat.

What is Ng-repeat explain with example?

How do I get all selected values of a multiple select box?

There are several ways in JavaScript to return the selected values in a multi-select dropdown.

Using for…of statement.
Using filter() with map() function.
Using selectedOptions property.
Using querySelectorAll() method.

How do you do ng-options?