Diamond problem is a common problem occurred in Object Oriented Programming, while using multiple-inheritance.

Consider the case where class C, is inherited from class A and class B. Suppose that both class A and class B have a method called foo().

Then when we are calling the method foo(), compiler cannot identify the exact method we are trying to use

• foo() from class A
• foo() from class B

This is called the diamond problem basically. There are some variants of this problem. To avoid this, there are multiple approaches. Java doesn't allow multiple inheritance. Hence the problem is avoided. But C++ is allowing multiple inheritance, therefore you must be careful to use of multiple inheritance.