Why [] not working on map for custom class

Question

Hi

Trying to create a map of int and custom class object as below:

Able to insert element using insert method but not working when I use subscript operator.

m[2] = obj is not working if m is declared as map<int,clsTest>

What's the issue here ?

https://code.sololearn.com/cjiVtbLzPZAU/?ref=app

Answer 1

[] of map need class object to be default constructible. Added default constructor and error is gone.