Filter uppercase with ng-options

You can easily use a css approach for this by attaching a class to the

var app = angular.module('myApp', []);
app.controller('ArrayController', function ($scope) {
    $scope.currency_list = [
      {
          code: 'eur'
      }, {
          code: 'usd'
      }
    ];
});
.text-capitalize{ text-transform: capitalize }
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app='myApp' ng-controller="ArrayController">
    <select 
      class="text-capitalize"
      ng-model="company.currency.code"
      ng-options="currency.code as currency.code for currency in currency_list">
    </select>
</div>

Use uppercase filter.

Take a look at this

var app = angular.module('myApp', []);
app.controller('ArrayController', function ($scope) {
    $scope.currency_list = [
    {
        code: 'eur'
    }, {
        code: 'usd'
    }
];
});
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app='myApp' ng-controller="ArrayController">
    <select ng-model="company.currency.code" ng-options="currency.code as (currency.code | uppercase) for currency in currency_list | uppercase">
</select>
</div>

This should work:

ng-options="currency.code as (currency.code | uppercase) for currency in currency_list"

See the filter docs: https://docs.angularjs.org/api/ng/filter/uppercase