Select

Overview for select

<mat-select> is a form control for selecting a value from a set of options, similar to the native <select> element. You can read more about selects in the Material Design spec. It is designed to work inside of a <mat-form-field> element.

To add options to the select, add <mat-option> elements to the <mat-select>. Each <mat-option> has a value property that can be used to set the value that will be selected if the user chooses this option. The content of the <mat-option> is what will be shown to the user.

Basic select

The <mat-select> supports 2-way binding to the value property without the need for Angular forms.

Select with 2-way value binding

You selected: option2

The <mat-select> also supports all of the form directives from the core FormsModule (NgModel) and ReactiveFormsModule (FormControl, FormGroup, etc.) As with native <select>, <mat-select> also supports a compareWith function. (Additional information about using a custom compareWith function can be found in the Angular forms documentation).

Select in a form

Selected value:

There are a number of <mat-form-field> features that can be used with any <mat-select>. These include error messages, hint text, prefix & suffix, and theming. For additional information about these features, see the form field documentation.

Select with form field features

The placeholder is a text label displayed in the select trigger area when no value is selected. When a value is selected, the placeholder will float above the select trigger area. The placeholder can be specified either via a placeholder attribute on the <mat-select> or a <mat-placeholder> element in the same form field as the <mat-select>. The <mat-form-field> also has additional options for changing the behavior of the placeholder. For more information see the form field placeholder documentation.

It is possible to disable the entire select or individual options in the select by using the disabled property on the <mat-select> and the <mat-option> components respectively.

Disabled select

 Disable select

If you want one of your options to reset the select's value, you can omit specifying its value.

Select with reset option

The <mat-optgroup> element can be used to group common options under a subheading. The name of the group can be set using the label property of <mat-optgroup>. Like individual <mat-option> elements, an entire <mat-optgroup> can be disabled or enabled by setting the disabled property on the group.

Select with option groups

<mat-select> defaults to single-selection mode, but can be configured to allow multiple selection by setting the multiple property. This will allow the user to select multiple values at once. When using the <mat-select> in multiple selection mode, its value will be a sorted list of all selected values rather than a single value.

Select with multiple selection

If you want to display a custom trigger label inside a select, you can use the <mat-select-trigger> element.

Select with custom trigger text

By default, when a user clicks on a <mat-option>, a ripple animation is shown. This can be disabled by setting the disableRipple property on <mat-select>.

Select with no option ripple

In order to facilitate easily styling the dropdown panel, <mat-select> has a panelClass property which can be used to apply additional CSS classes to the dropdown panel.

Select with custom panel styling

The <mat-form-field> allows you to associate error messages with your <mat-select>. By default, these error messages are shown when the control is invalid and either the user has interacted with (touched) the element or the parent form has been submitted. If you wish to override this behavior (e.g. to show the error as soon as the invalid control is dirty or when a parent form group is invalid), you can use the errorStateMatcher property of the <mat-select>. The property takes an instance of an ErrorStateMatcher object. An ErrorStateMatcher must implement a single method isErrorState which takes the FormControl for this <mat-select> as well as the parent form and returns a boolean indicating whether errors should be shown. (true indicating that they should be shown, and false indicating that they should not.)

Select with a custom ErrorStateMatcher
Errors appear instantly!

A global error state matcher can be specified by setting the ErrorStateMatcher provider. This applies to all inputs. For convenience, ShowOnDirtyErrorStateMatcher is available in order to globally cause input errors to show when the input is dirty and invalid.

@NgModule({
  providers: [
    {provide: ErrorStateMatcher, useClass: ShowOnDirtyErrorStateMatcher}
  ]
})
  • DOWN_ARROW: Focus next option
  • UP_ARROW: Focus previous option
  • ENTER or SPACE: Select focused item

The select component without text or label should be given a meaningful label via aria-label or aria-labelledby.

The select component has role="listbox" and options inside select have role="option".

This error is thrown if you attempt to bind the multiple property on <mat-select> to a dynamic value. (e.g. [multiple]="isMultiple" where the value of isMultiple changes over the course of the component's lifetime). If you need to change this dynamically, use ngIf or ngSwitch instead:

<mat-select *ngIf="isMultiple" multiple>
  ...
</mat-select>
<mat-select *ngIf="!isMultiple">
  ...
</mat-select>

This error is thrown if you attempt to assign a value other than null, undefined, or an array to a <mat-select multiple>. For example, something like mySelect.value = 'option1'. What you likely meant to do was mySelect.value = ['option1'].

This error occurs if you attempt to assign something other than a function to the compareWith property. For more information on proper usage of compareWith see the Angular forms documentation).
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