angular select 默认选中指定项，option动态渲染

<select ng-model="com.game_id" ng-options="x.game_id as x.game_name for x in game_info">
</select>
           

$scope.game_info =  [
            {game_id :  , game_name:'全部游戏'},
            {game_id :  , game_name:'穿越火线'},
            {game_id :  , game_name:'地下城与勇士'},
            {game_id :  , game_name:'使命召唤'},
            {game_id :  , game_name:'英雄联盟'},
            {game_id :  , game_name:'逆战'},
            ];
$scope.com = {
    game_id://指定项，
｝
           

如图所示：