Q:

orderBy doesn't work with ng-repeat

Am using orderBy to sort my  objects by their startdate. 
<ion-list>
<ion-item  ng-repeat="e in events | orderBy: e.startdate">
 <h4>{{e.name}}</h4>
 <h4>{{e.startdate}}</h4>
</ion-item>
</ion-list>

But it doen't work , how can i fix it please 

A:

By this:
<ion-list>
<ion-item  ng-repeat="e in events | orderBy: 'startdate'">
 <h4>{{e.name}}</h4>
 <h4>{{e.startdate}}</h4>
</ion-item>
</ion-list>

