Why does angularjs include an empty option in select

The empty option is generated when a value referenced by ng-model doesn't exist in a set of options passed to ng-options. This happens to prevent accidental model selection: AngularJS can see that the initial model is either undefined or not in the set of options and don't want to decide model value on its own.

If you want to get rid of the empty option just select an initial value in your controller, something like:

$scope.form.type = $scope.typeOptions[0].value;

Here is the jsFiddle: http://jsfiddle.net/MTfRD/3/

In short: the empty option means that no valid model is selected (by valid I mean: from the set of options). You need to select a valid model value to get rid of this empty option.

If you want an initial value, see @pkozlowski.opensource's answer, which FYI can also be implemented in the view (rather than in the controller) using ng-init:

<select ng-model="form.type" required="required" ng-init="form.type='bug'"
  ng-options="option.value as option.name for option in typeOptions" >
</select>

If you don't want an initial value, "a single hard-coded element, with the value set to an empty string, can be nested into the element. This element will then represent null or "not selected" option":

<select ng-model="form.type" required="required"
  ng-options="option.value as option.name for option in typeOptions" >
    <option style="display:none" value="">select a type</option>
</select>

For anyone out there that treat "null" as valid value for one of the options (so imagine that "null" is a value of one of the items in typeOptions in example below), I found that simplest way to make sure that automatically added option is hidden is to use ng-if.

<select ng-options="option.value as option.name for option in typeOptions">
    <option value="" ng-if="false"></option>
</select>

Why ng-if and not ng-hide? Because you want css selectors that would target first option inside above select to target "real" option, not the one that's hidden. It gets useful when you're using protractor for e2e testing and (for whatever reason) you use by.css() to target select options.

Maybe useful for someone:

If you want to use plain options instead of ng-options, you could do like below:

<select ng-model="sortorder" ng-init="sortorder='publish_date'">
  <option value="publish_date">Ascending</option>
  <option value="-publish_date">Descending</option>
</select>

Set the model inline. Use ng-init to get rid of empty option

Yes ng-model will create empty option value, when ng-model property undefined. We can avoid this, if we assign object to ng-model

Example

angular coding

$scope.collections = [
    { name: 'Feature', value: 'feature' }, 
    { name: 'Bug', value: 'bug' }, 
    { name: 'Enhancement', value: 'enhancement'}
];

$scope.selectedOption = $scope.collections[0];


<select class='form-control' data-ng-model='selectedOption' data-ng-options='item as item.name for item in collections'></select>

Important Note:

Assign object of array like $scope.collections[0] or $scope.collections[1] to ng-model, dont use object properties. if you are getting select option value from server, using call back function, assign object to ng-model

NOTE from Angular document

Note: ngModel compares by reference, not value. This is important when binding to an array of objects. see an example http://jsfiddle.net/qWzTb/

i have tried lot of times finally i found it.

Though both @pkozlowski.opensource's and @Mark's answers are correct, I'd like to share my slightly modified version where I always select the first item in the list, regardless of its value:

<select ng-options="option.value as option.name for option in typeOptions" ng-init="form.type=typeOptions[0].value">
</select>

I faced the same issue. If you are posting an angular form with normal post then you will face this issue, as angular don't allow you to set values for the options in the way you have used. If you get the value of "form.type" then you will find the right value. You have to post the angular object it self not the form post.

A simple solution is to set an option with a blank value "" I found this eliminates the extra undefined option.

Try this one in your controller, in the same order:

$scope.typeOptions = [
    { name: 'Feature', value: 'feature' }, 
    { name: 'Bug', value: 'bug' }, 
    { name: 'Enhancement', value: 'enhancement' }
];
$scope.form.type = $scope.typeOptions[0];

Here is the fix :

for a sample data like :

financeRef.pageCount = [{listCount:10,listName:modelStrings.COMMON_TEN_PAGE},    
{listCount:25,listName:modelStrings.COMMON_TWENTYFIVE_PAGE},
{listCount:50,listName:modelStrings.COMMON_FIFTY_PAGE}];

The select option should be like this:-

<select ng-model="financeRef.financeLimit" ng-change="financeRef.updateRecords(1)" 
class="perPageCount" ng-show="financeRef.showTable" ng-init="financeRef.financeLimit=10"
ng-options="value.listCount as value.listName for  value in financeRef.pageCount"
></select>

The point being when we write value.listCount as value.listName, it automatically populates the text in value.listName but the value of the selected option is value.listCount although the values my show normal 0,1,2 .. and so on !!!

In my case, the financeRef.financeLimit is actually grabbing the value.listCount and I can do my manipulation in the controller dynamically.

Simple fix will be :

select option:empty { display:none }

Hope it helps someone.