What does default mean in C++?

A default argument is a value provided in a function declaration that is automatically assigned by the compiler if the caller of the function doesn’t provide a value for the argument with a default value . In case any value is passed the default value is overridden.

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Is a constructor mandatory for a class?

Users do not need to write constructors for every class . A constructor can be declared using any of the access modifiers. It is mandatory to have a constructor with the right access modifier. However, the compiler supplies a default if an access modifier is not defined in the class and a constructor is not declared.

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