Why is there always a constructor in C++ OOP?

The constructor made by the compiler would look like this in normal code:

myClass::myClass() {}

As you can see, it is completely blank. Inside the compiler it must be able to create an object so that you can use it in your code, the constructor will set all the operators up and fix them so that you can call it :

myClass object;

It also creates a 'new' object and the ability to have arrays:

myClass * object = new object[5];

Hope this helps! Good luck.

No it does not, it calls the constructor function, it doesn't make one. To make an instance of an object the object MUST have a Constructor as one of it's methods, this method is called when you create a instance of your object and will initialize your object. Most of the time you are just setting variables to their starting or given values if the Constructor has parameters.

If you try to make an instance that does not have a constructor either your program will crash or will not function correctly.