1 way to do it:
Person squid;
void setup() {
frameRate(1);
squid = new Person();
}
void draw() {
squid.increaseAge(); // alt.: ++squid.age;
print(squid);
}
class Person {
int age;
Person increaseAge() {
++age;
return this;
}
String toString() {
return "Age: " + age + TAB;
}
}