Wen is a default agreement value used inside a function?

Question

Please answer this on the basis of C++

Answer 1

Did you mean 'default argument'? If that is the case, the default value of an argument is used when no value is specified for the parameter when the function is called. Have a look at the lesson from the C++ course:
https://www.sololearn.com/learn/CPlusPlus/1639/