Runtime Error - Cannot Read Property Of Undefined

ok, to fix this erorr, this is one of the scenario i had when i got this error.

in my typescript file i had declared a public variable as

QuizResults:any;

and in my html template i had called it as

<pre>QuizResults {{QuizResults |json}}</pre>

the output showed there was a property called Response from the JSON data i got, so when i try to display the Response property, like this in my html template:

<pre>QuizResults {{QuizResults.Response |json}}</pre>

thats when i got the error that said:

Runtime Error Error in ./ResultsPage class ResultsPage - caused by: Cannot read property 'Response' of undefined

to fix this error, i had to change the declaration of the variable in the typescript file to this:

QuizResults={};

You see the difference? hope this helps, note, you could also declare it as:

QuizResults:any={};