Cannot read property of 'xxx' of undefined

Question

I\'m using Ionic 2, in which a component has two components and the data were shared using emitters. But when I execute the program, it comes to this error.

Answer 1

The view is loaded before billItem is set.

You could use a safe navigation operator ?.

 //billItem model has BillNo property

or set it to empty object in the constructor of bill-details.ts:

constructor(...){
  if(! this.billItem){
    this.billItem={}
  }
}