How to make a preselection for a select list generated by AngularJS?

Asked 12/1, 2013 at 20:17 Answered 11/12, 2020 at 6:41

<select ng-model="team.captain" ng-options="player.name for player in team.players"></select>

This correctly creates a select list to choose the team captain. However, by default a blank option is selected. How can we preselect the first player from the list instead?

<select ng-model="team.captain" ng-options="player.name for player in team.players" class="ng-pristine ng-valid">
  <option value="0">John</option>
  <option value="1">Bobby</option>
</select>

I tried adding ng-init="team.captain='0'" but that didn't help.

Update Apparently this happens because

a value referenced by ng-model doesn't exist in a set of options passed to ng-options.

Source: Why does AngularJS include an empty option in select?

However, the question still remains why using ng-init doesn't work?

<select ng-init="team.captain='0'" ng-model="team.captain" ng-options="player.name for player in team.players"></select>

Shampoo answered 12/1, 2013 at 20:17 Comment(1)

You can solve with this Magic Trick: https://mcmap.net/q/472733/-angularjs-select-preselect-not-working – Domingo 1/8, 2016 at 13:58

Here's what worked:

<select ng-init="team.captain=team.players[0]" 
        ng-model="team.captain" 
        ng-options="player.name for player in team.players"></select>

And what didn't work:

ng-init="team.captain='0'"
ng-init="team.captain='John'"

My guess is that Angular goes beyond simple comparison of values or labels. It probably compares object references.

Shampoo answered 12/1, 2013 at 21:2 Comment(2)

I should have mentioned in my answer that the "label" value needs to be reference to the same object in the array. In other words, this won't work either: ng-init="{name: 'John'}" – Susysuter 12/1, 2013 at 21:4

In case anyone here is trying to achieve the same thing with angular material md-select then check out this answer https://mcmap.net/q/166489/-initializing-select-with-angularjs-and-ng-repeat – Targe 29/7, 2016 at 5:42

Here's an alternate method for initializing a drop down menu using AngularJS.

(working example on JS Fiddle: http://jsfiddle.net/galeroy/100ho18L/1/)

<head>
    <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/angularjs/1.2.26/angular.min.js"></script>
</head>

<body ng-app="" ng-controller="myController">

    <select 
        ng-model="carSelection"
        ng-options = "x.make for x in cars">
    </select>

    <script>

        function myController($scope) {

            $scope.cars = [
                {"make": "Nissan", "model": "Sentra"},
                {"make": "Honda", "model": "Prelude"},
                {"make": "Toyota", "model": "Prius"}
            ]

            $scope.carSelection = $scope.cars[1]; // this line initializes the drop down menu
        }

    </script>

</body>

Luffa answered 17/1, 2015 at 0:12 Comment(2)

hey you seem like familiar with initializing combo boxes , just question if it doesn't bother you , this one if you have one select box ope.carSelection = $scope.cars[1]; what if i want to initialize in a dynamic number of combo boxes and i want to initilize them all the same value what would i do here's my question #37351551 and thank you – Sproul 23/5, 2016 at 8:58

key that it had to be a reference to the same object, I tried using a different object with a corresponding id. +1 – Carlie 6/3, 2017 at 23:49

As @camus already mentioned in a comment, you need to set the model to a valid "label" value (or reference), not an index value. This is a bit odd since you can see an index value being used in the HTML.

Angular sets the value attributes in the HTML as follows:

when using array as datasource, it will be the index of array element in each iteration;
when using object as datasource, it will be the property name in each iteration.

When an item is selected, Angular looks up the correct entry in the array/object based on the index or property name.

Susysuter answered 12/1, 2013 at 20:52 Comment(0)

What about ng-selected, as seen in this jsfiddle:

<select ng-model="val">
  <option ng-repeat="opt in options" ng-selected="$first">
    {{ opt }}
  </option>
</select>

Conjuncture answered 12/3, 2016 at 11:41 Comment(1)

It worked but when used on option tag instead of select – Halifax 30/7, 2016 at 4:30

I achieved this using ng-model and ng-options.Basically your model and ng-options should be in sync.

When my model (projIndustry in this case) was initialized to some number then I had to use ind.ID in ng-options.(ID comparison).
When my model was initialized to object ,then I had to use ind(object) in ng-options.(Object comparison)

<select data-ng-options="ind.ID as ind.Display_Text for ind in arrIndustries" 
 data-ng-model="projIndustry" ng-change="onIndChange()" />

Oleta answered 5/9, 2017 at 7:29 Comment(1)

nice approach !! – Stipendiary 5/9, 2017 at 7:35

In case you are using angular 2+, here is what worked. `

<mat-select matNativeControl placeholder="Select Item" [(ngModel)]="selectedItem" name="selectedCaseStudyName" (selectionChange)="onSelectionChangeHandler($event)" [ngStyle]="{'background-color':'silver'}">

        <mat-option *ngFor="let item of myItemList" [value]="item.ItemName">
            {{item.ItemName}}
        </mat-option>
    </mat-select>`

In .ts,

'selectedItem = myItemList[2].ItemName'

myItemList is list of objects with one of the fields being ItemName. Important point is to bind [(ngModel)] to variable selectedItem and then initialize it with the required index of the list. Whenever you bind [(ngModule)], make sure that you import NgModule

import {ngModule} from '@angular/core';

Leveloff answered 11/12, 2020 at 6:41 Comment(0)

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