Remove blank select option Angularjs

Question

Good afternoon, I need to remove the blank line that comes as default in the select of Angularjs, I would like to put a default value in place of the blank line. I researched several forums and tried many options but nothing worked. can help me?

<div class="col-md-3">
    <label>SubClasse</label>
    <select ng-model="modelcompraevenda.subClasse" class="form-control">
        <option  ng-selected="data.unit == 2"  ng-selected="true"  ng-repeat="z in modelcompraevenda.listSubClasses" value="{{z.id}}">{{z.descricao}}</option>
    </select>
</div>

Answer 1

You need to set an initial value for your model, this way:

$scope.modelcompraevenda.subClasse = $scope.modelcompraevenda.listSubClasse[0];

Answer 2

I solved it! follows solution:

<div class="col-md-3">
     <label>SubClasse</label>
     <select ng-model="modelcompraevenda.subClasse" class="form-control" style="z-index:0" ng-options="z.descricao for z in modelcompraevenda.listSubClasses track by z.id">
     </select>
</div>