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Jupyter at Bryn Mawr College |
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| Public notebooks: /services/public/dblank / CS110 Intro to Computing / 2017-Fall / Notebooks | |||
Object-Oriented Programming¶
Review of terms:
- class
- instance
- method
- global variables
- types/classes with lowercase first letters are primitives (int, float, double, boolean)
- constructor (none needed if no paramaters)
- this
- parameters, arguments
In [4]:
class Human {
String name;
Human(String x) {
name = x;
}
void speak() {
println("I'm a human");
}
}
class Monkey {
void speak() {
println("I'm a monkey");
}
}
Human human0;
Human human1;
Monkey monkey0;
void setup() {
human0 = new Human("Kevin");
human1 = new Human("Sylvia");
monkey0 = new Monkey();
}
void draw() {
human0.speak();
human1.speak();
monkey0.speak();
noLoop();
}
Arrays of Objects¶
Review of ideas:
- array
- declare array
- create space for the array
- create the instances
In [13]:
class Human {
void speak() {
println("I'm a human");
}
}
class Monkey {
void speak() {
println("I'm a monkey");
}
}
Human[] human = new Human[25];
Monkey[] monkey = new Monkey[25];
void setup() {
for (int i=0; i < human.length; i++) {
human[i] = new Human();
}
for (int i=0; i < monkey.length; i++) {
monkey[i] = new Monkey();
}
}
void draw() {
for (int i=0; i < human.length; i++) {
human[i].speak();
}
for (int i=0; i < monkey.length; i++) {
monkey[i].speak();
}
noLoop();
}
Object-Oriented Programming - Inheritance¶
In [5]:
class Primate {
void speak() {
println("I'm a primate");
}
}
class Human extends Primate {
void speak() {
println("I'm a human");
}
}
class Monkey extends Primate {
void speak() {
println("I'm a monkey");
}
}
Primate primate0;
Human human0;
Monkey monkey0;
void setup() {
primate0 = new Primate();
human0 = new Human();
monkey0 = new Monkey();
}
void draw() {
primate0.speak();
human0.speak();
monkey0.speak();
noLoop();
}
In [5]:
class Primate {
void speak() {
println("I'm a primate");
}
}
class Human extends Primate {
void speak() {
println("I'm a human");
}
}
class Monkey extends Primate {
void speak() {
println("I'm a monkey");
}
}
class SpiderMonkey extends Monkey {
void speak() {
println("eeee eee ooo oo");
}
}
Primate[] primate = new Primate[25];
void setup() {
for (int i=0; i < primate.length; i++) {
if (i % 2 == 0) {
primate[i] = new Human();
} else {
primate[i] = new Monkey();
}
}
}
void draw() {
for (int i=0; i < primate.length; i++) {
primate[i].speak();
}
noLoop();
}
New ideas:
- extend a class
- subclass
- super class, or base class
- method overrides
polymorphism
Primate is the base class, or super class
- Human and Monkey are subclasses
- Treating all of the objects the same, but having the methods do their specifics: polymorphism
See pages 223 - 232 of your textbook for additional information.