Class Casting with ArrayList ?

  • Thread starter Thread starter Cybertof
  • Start date Start date
C

Cybertof

Hello,

In the code below, is there a shortcut not to use the temp var
CurrEmployee ?

I would like to use something like
"if (Employee)MyArrayList.Name"
but don't know the syntax....


*******
CODE : (MyArrayList is a list of Employee)
*******
Employee CurrEmployee;
for (int i = 0;i<MyArrayList.Length;i++)
{

CurrEmployee = MyArrayList;
if (CurrEmplyee.Name == "test")
{
}
}


Regards,
Cybertof.
 
I don't think you can do this in the way that you mean.

The only other option to the one you already have is to have a static method
in your Employee class called

Convert(object obj)

whihc returned an Employee object.

so you'd end up with something like

for (int i = 0;i<MyArrayList.Length;i++)
{
if ( Employee.Convert( MyArrayList ).Name == "test" )
{
}
}

hope that helps.

Dan.

Hello,

In the code below, is there a shortcut not to use the temp var
CurrEmployee ?

I would like to use something like
"if (Employee)MyArrayList.Name"
but don't know the syntax....


*******
CODE : (MyArrayList is a list of Employee)
*******
Employee CurrEmployee;
for (int i = 0;i<MyArrayList.Length;i++)
{

CurrEmployee = MyArrayList;
if (CurrEmplyee.Name == "test")
{
}
}


Regards,
Cybertof.
 
Cybertof said:
In the code below, is there a shortcut not to use the temp var
CurrEmployee ?

I would like to use something like
"if (Employee)MyArrayList.Name"
but don't know the syntax....
Click to expand...
*******
CODE : (MyArrayList is a list of Employee)
*******
Employee CurrEmployee;
for (int i = 0;i<MyArrayList.Length;i++)
{

CurrEmployee = MyArrayList;
if (CurrEmplyee.Name == "test")
{
}
}
Click to expand...


Well, you could improve the code above by declaring the variable inside
the loop:

for (int i=0; i < MyArrayList.Length; i++)
{
Employee CurrEmployee = (Employee) MyArrayList;
if (CurrEmployee.Name=="test")
{
}
}

or, for preference, you could use a foreach loop:

foreach (Employee CurrEmployee in MyArrayList)
{
if (CurrEmployee.Name=="test")
{
}
}

You *could* cast directly, but I wouldn't recommend it (as I reckon the
above is more readable):

for (int i=0; i < MyArrayList.Length; i++)
{
if (((Employee)(MyArrayList)).Name=="test")
{
}
}
 
Daniel & Jon,

Thanks a lot for your advises.

The newsgroup is a great knowledge place !

Regards,
Cybertof.
 
Jon,

could you give me your opinion on the question I asked today two hours
before this one was posted. ("string or stream")

thanks.
Dan.

Cybertof said:
In the code below, is there a shortcut not to use the temp var
CurrEmployee ?

I would like to use something like
"if (Employee)MyArrayList.Name"
but don't know the syntax....
Click to expand...
*******
CODE : (MyArrayList is a list of Employee)
*******
Employee CurrEmployee;
for (int i = 0;i<MyArrayList.Length;i++)
{

CurrEmployee = MyArrayList;
if (CurrEmplyee.Name == "test")
{
}
}
Click to expand...


Well, you could improve the code above by declaring the variable inside
the loop:

for (int i=0; i < MyArrayList.Length; i++)
{
Employee CurrEmployee = (Employee) MyArrayList;
if (CurrEmployee.Name=="test")
{
}
}

or, for preference, you could use a foreach loop:

foreach (Employee CurrEmployee in MyArrayList)
{
if (CurrEmployee.Name=="test")
{
}
}

You *could* cast directly, but I wouldn't recommend it (as I reckon the
above is more readable):

for (int i=0; i < MyArrayList.Length; i++)
{
if (((Employee)(MyArrayList)).Name=="test")
{
}
}
 
In your 3 versions, which is the best one regarding 'performance' ?
I mean :less memory consumming, less object creation, fastest speed...


Thanks,
Cybertof.
 
Cybertof said:
In your 3 versions, which is the best one regarding 'performance' ?
I mean :less memory consumming, less object creation, fastest speed...
Click to expand...

They're likely to be pretty much identical - but there's an important
thing to note here, which is that you shouldn't worry about that kind
of thing unless it proves to be an issue. Readability is far more
important than performance for most code - chances are it's only going
to be a tiny part of your code which ends up as the bottleneck, so only
think about sacrificing readability for performance when you know
exactly where that is.
 
... but there's an important thing to note here,
which is that you shouldn't worry about that kind
of thing unless it proves to be an issue.
Readability is far more important than performance
for most code - chances are it's only going to be
a tiny part of your code which ends up as the
bottleneck, so only think about sacrificing
readability for performance when you know
exactly where that is.
Click to expand...


Hear! Hear!

-- Rick
 
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