Identifiers & declarations
Identifiers are a sequence of letters, digits and underscores starting
with a letter, and with no restriction on length. They are used to
give a name to a user-defined object, e.g. variable, struct, function,
etc. Every name in a C++ program must be declared before it is used.
int v1, v2;
in the program above declares two integer variables
with identifiers v1
and v2
.