Question about "enums"

[mdh]

In one of the answers to a K&R exercise, the first couple of lines are:

enum loop { NO, YES};
enum loop okloop=YES;

I get the first line, but not the second.

Sorry about the LOL question.

Thanks in advance

[Ian Collins]

mdh wrote:

In one of the answers to a K&R exercise, the first couple of lines are:

enum loop { NO, YES};
enum loop okloop=YES;

oklopp us a variable of the enum type loop, so you can assign either NO
or YES to it.

--
Ian Collins.

[mdh]

Ian Collins wrote:

oklopp us a variable of the enum type loop, so you can assign either NO
or YES to it.

It must be late or too much C :-)

I guess what I am missing is what the:

enum loop { YES,NO}

then does?

I thought that the idea behind this was to assign an integer to the
YES, NO? ( In this case 0 and 1?)

Then why not simply use the terms "YES" and "NO"?

Thanks in advance?

[Ian Collins]

mdh wrote:

Ian Collins wrote:

oklopp us a variable of the enum type loop, so you can assign either NO
or YES to it.

It must be late or too much C :-)

I guess what I am missing is what the:

enum loop { YES,NO}

then does?

An enum is a type, which in this case can have one of two values, YES
and NO.

Assigning any other value to a loop is undefined. Unfortunately C
compilers don't regard this as an error, which renders enums little more
than symbolic constants.
I thought that the idea behind this was to assign an integer to the
YES, NO? ( In this case 0 and 1?)

Then why not simply use the terms "YES" and "NO"?

you can,

int n = YES;

Is perfectly OK.

--
Ian Collins.

[CBFalconer]

mdh wrote:

In one of the answers to a K&R exercise, the first couple of lines
are:

enum loop { NO, YES};
enum loop okloop=YES;

I get the first line, but not the second.

Then separate the second line into its components:

enum loop okloop;

okloop = YES;

and the three lines are: type declaration, var declaration,
assignment.

--
"Churchill and Bush can both be considered wartime leaders, just
as Secretariat and Mr Ed were both horses." - James Rhodes.
"We have always known that heedless self-interest was bad
morals. We now know that it is bad economics" - FDR

[mdh]

CBFalconer wrote:

Then separate the second line into its components:

Thank you both Ian and CBF for that explanation.

[venkatesh]

u can make use of okloop whereever u want "1"
if if is not that please correct me

[Ian Collins]

venkatesh wrote:

u can make use of okloop whereever u want "1"
if if is not that please correct me

What are you replying to? Please quote the context.

Assuming you are refereing to:

enum loop { NO, YES};
enum loop okloop=YES;

You would use loop whenever you wanted YES. Use an enum for what it is,
if you wanted a synonym for 1, use a const (unsigned) int.

--
Ian Collins.

[Bill Pursell]

Ian Collins wrote:

mdh wrote:

Ian Collins wrote:

oklopp us a variable of the enum type loop, so you can assign either NO
or YES to it.

An enum is a type, which in this case can have one of two values, YES
and NO.

Assigning any other value to a loop is undefined. Unfortunately C
compilers don't regard this as an error, which renders enums little more
than symbolic constants.

gcc gives a warning when you do a switch on an enum type, indicating
that you have failed to explicitely specify behavior for any of the
listed cases. I find that very useful.

[Ian Collins]

Bill Pursell wrote:

Ian Collins wrote:

mdh wrote:

Ian Collins wrote:
oklopp us a variable of the enum type loop, so you can assign either NO
or YES to it.

An enum is a type, which in this case can have one of two values, YES
and NO.

Assigning any other value to a loop is undefined. Unfortunately C
compilers don't regard this as an error, which renders enums little more
than symbolic constants.

gcc gives a warning when you do a switch on an enum type, indicating
that you have failed to explicitely specify behavior for any of the
listed cases. I find that very useful.

But not with the following, which I've always considered a huge hole in
the C standard.

enum loop { NO, YES};
enum loop okloop=YES;

void f( enum loop v )
{
}

int main(void)
{
f( 42 );

okloop = 42;

return 0;
}

--
Ian Collins.