class declaration

see posted files for examples

declaration usually given in header

method prototypes and fields

definition of methods given in source file using ClassName::

three access modifiers

public, protected, private

private by default

constructors

if no constructor given, compiler provides implicit zero-argument constructor

compiler also provides implicit copy constructor

a copy constructor is used whenever an instance is being copied

passed by value

a new instance is being constructed from an existing instance

the default copy constructor just tries to copy over each field (perhaps invoking additional copy constructors)

a copy-constructor by definition takes a reference
parameter (else we’d need to copy the parameter, but
that’s what we’re defining!) of the same type

destructor

used to “clean up” an instance

called when an instance is deallocated by delete

called automatically for stack-allocated instances

operator overloading

Rule of Three: if you implement one of the following, then you probably need to implement all three

copy constructor

destructor

assignment operator

copy constructor vs. assignment

copy constructor initializes a new bag of bits (new
variable or parameter)

assignment (=) replaces an existing value with a new
one – may need to clean up old state (free heap data?)

overload << if you want to be able to print your object with cout

analogus to overloading toString in Java