I am new to Angular2 and here I am trying to loop through the array mmEditorTypes and checking the condition, if the condition is satisfied then I'll be executing the open method.

But whenever i execute the below code, I am getting this error :

portalModeService: loading of portalMode threw exception:

TypeError: Cannot read property 'forEach' of undefined.

Could someone let me know how to fix this error?

porta.service.ts :

function isAppContained(viewState, appType){

      let angular:any;

      let isContained = false;

      angular.forEach(viewState.appViewStates, function (appViewState) {

        if (appViewState.signature.appType === appType) {

          isContained = true;

        }

      });

      return isContained;

    }