"is a" Vs "has a"

[Sadaf Zaidi]

Please tell me about "is a " and "has a".
Thanks

[Rikard Qvarforth]

Hello ..
well a cat "is a" animal .. ok ?
..in java that is = "class Cat extends Animal" a animal can be a cat ..
and a cat "has a" mjaiu call
.. in java that is
class cat extends animal{
private String soundCall = "mjaiu";
}
the "has a" is exclusive to the class .. but look at this
a person "is a" human .. class person extends human
a person "has a" head .. class person implements head
person nisse = new person();
so nisse "has a" head but a cat can also have a head..
class cat extends animal implements head
hope this helps ..
my english is sucks .. hummm

[Fei Ng]

Try reading this...
http://www.javaranch.com/campfire/StoryPoly.jsp

[William Barnes]

my english is ****

I understood everything fine except for "mjaiu".

[Marilyn de Queiroz]

"mjaiu" = "meow"

[Rikard Qvarforth]

he he well my cat at home is litle strange

[Sadaf Zaidi]

Thanks for all of your replies but, yet its not clear to me.
[This message has been edited by Sadaf Zaidi (edited November 25, 2001).]

[Marilyn de Queiroz]

<font size=2>
class Computer extends Machine // Computer is a machine (not Computer has Machine)
{
    int megsOfMemory = 80 ; // Computer has memory (not Computer is memory)
}
  
class Animal{}
 
class Cat extends Animal{} // Cat is an Animal (not Cat has an Animal)
  
class Person{}
 
class SadafZaidi extends Person // Sadaf Zaidi "is a" person (not Sadaf Zaidi has a person 
                                //although that may be also true in another context) 
{
    Computer comp = new Computer(); // Sadaf Zaidi "has a" computer (not Sadaf Zaidi is a Computer)
    Animal cat = new Cat() ; // Sadaf Zaidi has a cat (not Sadaf Zaidi is a cat)
}

[Sadaf Zaidi]

Thank you Marilyn deQueiroz .Its clear now.