By default, C++ will treat any constructor as an implicit conversion operator. Consider the following case: #include <cassert> #include <iostream> class Fraction { private: int m_numerator; int m_denominator; public: // Default constructor Fraction(int numerator = 0, int denominator = 1) : m_numerator(numerator), m_denominator(denominator) { assert(denominator != 0); } // Copy …
Consider the following line of code: int x = 5; This statement uses copy initialization to initialize newly created integer variable x to the value of 5. However, classes are a little more complicated, since they use constructors for initialization. This lesson will examine topics related to copy initialization for …
In the previous lesson, we overloaded operator+ as a friend function: #include <iostream> class Cents { private: int m_cents{}; public: Cents(int cents) : m_cents{ cents } {} // add Cents + Cents using a friend function friend Cents operator+(const Cents& c1, const Cents& c2); int getCents() const { return m_cents; …
Most programs that have a user interface of some kind need to handle user input. In the programs that you have been writing, you have been using std::cin to ask the user to enter text input. Because text input is so free-form (the user can enter anything), it’s very easy …
The concepts of scope, duration, and linkage cause a lot of confusion, so we’re going to take an extra lesson to summarize everything. Some of these things we haven’t covered yet, and they’re here just for completeness / reference later. An identifier’s scope determines where the identifier can be accessed …
In lesson , we noted that a variable or function identifier can only have one definition (the one definition rule). Thus, a program that defines a variable identifier more than once will cause a compile error: int main() { int x; // this is a definition for variable x int …
In this chapter, we explored the meat of C++ — object-oriented programming! This is the most important chapter in the tutorial series. Classes allow you to create your own data types that bundle both data and functions that work on that data. Data and functions inside the class are called …
When writing a class that has multiple constructors (which is most of them), having to specify default values for all members in each constructor results in redundant code. If you update the default value for a member, you need to touch each constructor. It’s possible to give normal class member …
Another chapter down! The next chapter is the best one, and you’re almost there! There’s just this pesky quiz to get past… Function arguments can be passed by value, reference or address. Use pass by value for fundamental data types and enumerators. Use pass by reference for structs, classes, or …
In lesson , we introduced std::vector and talked about how std::vector can be used as a dynamic array that both remembers its length and can be dynamically resized as required. Although this is the most useful and commonly used part of std::vector, std::vector has some additional attributes and capabilities that …
