enumeration

[Web Developer]

Hi,

Java doe not have the data type enum. I am starting to learn it in Java and
find it confusing.

1) Whats the point in having enum? Java does have it, so probably there is a
way around it.
2) Can someone show a SIMPLE code of how enum works?


WD

 

[Victor Bazarov]

Java doe not have the data type enum. I am starting to learn it in Java and
find it confusing.

Find what confusing? Java? No doubt.

1) Whats the point in having enum? Java does have it, so probably there is a
way around it.

Enums are "named constants". Each enum is its own type. Using enums
promotes strong typing (no, I don't mean hitting keys with your fingers).

2) Can someone show a SIMPLE code of how enum works?

#include <iostream>

enum Protocol { FTP = 21, HTTP = 80, HTTPS = 143 };

void foo(int)
{
std::cout << "foo(int) called\n";
}

void foo(Protocol)
{
std::cout << "foo(Protocol) called\n";
}

int main()
{
foo(42);
foo(HTTPS); // _not_ the same as foo(143)
}

Victor

 

[Alexander Terekhov]

Hi,

Java doe not have the data type enum. I am starting to learn it in Java and
find it confusing.

1) Whats the point in having enum? Java does have it, so probably there is a
way around it.
No.

2) Can someone show a SIMPLE code of how enum works?

Yes.

#include <iostream>

enum vote { no, yes };

std:stream& operator <<(std:stream& os, vote v) {
return os << (!v ? "no" : "yes");
}

vote operator or(vote lhs, vote rhs) {
return vote(lhs | rhs);
}

int main() {
std::cout << (yes or no) << std::endl;
}

Well, try also this:

#include <cstdio>
#include <climits>
//#include <iostream>

int main() {
enum { iMIN = LONG_MIN, uMAX = ULONG_MAX } ld = iMIN, lu = uMAX;
printf("%ld ** %lu\n", LONG_MIN, ULONG_MAX);
printf("%ld ** %lu\n", static_cast<signed long>(ld),
static_cast<unsigned long>(lu));
// std::cout << ld << " ** " << lu << std::endl;
}

regards,
alexander.

 

[Stewart Gordon]

Hi,

Java doe not have the data type enum. I am starting to learn it in Java and
find it confusing.

Well, this is a C++ 'group, not a Java 'group.

1) Whats the point in having enum? Java does have it, so probably there is a
way around it.

But you just said "Java doe not have" it.

2) Can someone show a SIMPLE code of how enum works?

If there's any C++ question buried in this, please clarify what you're
asking for. Otherwise, try asking in comp.lang.java.help.

Stewart.

 

[Razmig K]

Dear mate,

There's a little survey about the general uses of 'enum's started by
me in comp.lang.c++ under the title "C++ programmers! How do you use
your 'enum's ?", and in comp.lang.c under the title "C programmers!
How do you use your 'enum's ?".
You may find these two threads useful.

Regards,
//rk