Hi,
Say I have an array of objects of type "Person" (ie. Person[]) and each
Person object in the array has a property "Name" (ie. Person.Name), is
there a simple way of telling whether an object exists in the array that
has a specific value for the Name property?
This is what I want to do in pseudo-code:
----
Person[] people = myGetPeopleArrayMethod();
if (people.ContainsAPersonWithNameEquals("Fred"))
{
Person myPerson = people.GetThePersonWithName("Fred");
// Do things with "Fred"
...
}
----
Is there a simple way to do the above? I don't necessarily want to
create all of those methods listed above, in fact if it can be done in
fewer steps, that would be even better.
Cheers,
--
Dylan Parry http://electricfreedom.org | http://webpageworkshop.co.uk
The opinions stated above are not necessarily representative of
those of my cats. All opinions expressed are entirely your own. 7 2522
Array.Find:
Person fred = Array.Find<Person>(people, delegate(Person
person)
{
return person.Name == "Fred";
});
you might be able to drop the <Personthere... or even easier in C# 3
(still against .NET 2.0):
Person fred = Array.Find(people, person =person.Name ==
"Fred");
then:
if(fred != null)
{ // Do things with "Fred"
}
Marc
In C# 3.5:
People[] freds = Array.FindAll(people, p =p.FirstName == "Fred");
if(freds != null && freds.Length != 0)
{
// do things with freds
}
In C# 2.0:
People[] freds = Array.FindAll(people, delegate(Person p)
{
return p.FirstName == "Fred";
});
if(freds != null && freds.Length != 0)
{
// do things with freds
}
You could perform a contains check with Array.IndexOf first, but that
would involve 2 scans through the array.
Terry.
On Jun 16, 12:23 pm, Dylan Parry <use...@dylanparry.comwrote:
Hi,
Say I have an array of objects of type "Person" (ie. Person[]) and each
Person object in the array has a property "Name" (ie. Person.Name), is
there a simple way of telling whether an object exists in the array that
has a specific value for the Name property?
This is what I want to do in pseudo-code:
----
Person[] people = myGetPeopleArrayMethod();
if (people.ContainsAPersonWithNameEquals("Fred"))
{
Person myPerson = people.GetThePersonWithName("Fred");
// Do things with "Fred"
...}
----
Is there a simple way to do the above? I don't necessarily want to
create all of those methods listed above, in fact if it can be done in
fewer steps, that would be even better.
Cheers,
--
Dylan Parryhttp://electricfreedom.org|http://webpageworkshop.co.uk
The opinions stated above are not necessarily representative of
those of my cats. All opinions expressed are entirely your own.
Dylan Parry wrote:
Is there a simple way to do the above?
[...]
Thanks to all that replied. As I'm able to use 3.5, I've gone with the
LINQ solution. I did eventually come up with something similar myself,
but it was much more complicated and not at all elegant!
--
Dylan Parry http://electricfreedom.org | http://webpageworkshop.co.uk
The opinions stated above are not necessarily representative of
those of my cats. All opinions expressed are entirely your own.
On Jun 16, 4:23*pm, Dylan Parry <use...@dylanparry.comwrote:
Hi,
Say I have an array of objects of type "Person" (ie. Person[]) and each
Person object in the array has a property "Name" (ie. Person.Name), is
there a simple way of telling whether an object exists in the array that
has a specific value for the Name property?
This is what I want to do in pseudo-code:
----
Person[] people = myGetPeopleArrayMethod();
if (people.ContainsAPersonWithNameEquals("Fred"))
{
* * Person myPerson = people.GetThePersonWithName("Fred");
* * // Do things with "Fred"
* * ...}
----
Is there a simple way to do the above? I don't necessarily want to
create all of those methods listed above, in fact if it can be done in
fewer steps, that would be even better.
Cheers,
--
Dylan Parryhttp://electricfreedom.org|http://webpageworkshop.co.uk
The opinions stated above are not necessarily representative of
those of my cats. All opinions expressed are entirely your own.
C# 3.5
class Program
{
static void Main(string[] args)
{
List<Personpersons = GetPersons();
foreach (Person per in persons.Where(p =p.Name ==
"Fred"))
{
Console.WriteLine(per.Name);
}
Console.ReadLine();
}
public static List<PersonGetPersons()
{
List<Personpersons = new List<Person>();
persons.Add(new Person("Alex"));
persons.Add(new Person("Robert"));
persons.Add(new Person("Fred"));
persons.Add(new Person("Freak"));
persons.Add(new Person("Google"));
persons.Add(new Person("App"));
return persons;
}
}
This should work!!!
On Jun 16, 4:23*pm, Dylan Parry <use...@dylanparry.comwrote:
Hi,
Say I have an array of objects of type "Person" (ie. Person[]) and each
Person object in the array has a property "Name" (ie. Person.Name), is
there a simple way of telling whether an object exists in the array that
has a specific value for the Name property?
This is what I want to do in pseudo-code:
----
Person[] people = myGetPeopleArrayMethod();
if (people.ContainsAPersonWithNameEquals("Fred"))
{
* * Person myPerson = people.GetThePersonWithName("Fred");
* * // Do things with "Fred"
* * ...}
----
Is there a simple way to do the above? I don't necessarily want to
create all of those methods listed above, in fact if it can be done in
fewer steps, that would be even better.
Cheers,
--
Dylan Parryhttp://electricfreedom.org|http://webpageworkshop.co.uk
The opinions stated above are not necessarily representative of
those of my cats. All opinions expressed are entirely your own.
C# 2.0
List<Personpersons = GetPersons();
Predicate<Personpred = delegate(Person p)
{
return p.Name == "Fred";
};
List<Personmatches = persons.FindAll(pred);
-Cnu
C# 3.5
Pedant mode; there is no C# 3.5; that is C# 3 (from the lambda)
using .NET 3.5 - or actually it could be .NET 2.0 with LINQBridge or
any other similar LINQ-to-objects implementation. Either way, the
beauty of LINQ on IEnumerable<Tis that it will work even with the
OP's original array design (you don't need the List<T>).
Marc
On Jun 16, 5:09*pm, Marc Gravell <marc.grav...@gmail.comwrote:
C# 3.5
Pedant mode; there is no C# 3.5; that is C# 3 (from the lambda)
using .NET 3.5 - or actually it could be .NET 2.0 with LINQBridge or
any other similar LINQ-to-objects implementation. Either way, the
beauty of LINQ on IEnumerable<Tis that it will work even with the
OP's original array design (you don't need the List<T>).
Marc
Thanks for the info. I think you are right. This thread has been closed and replies have been disabled. Please start a new discussion. Similar topics
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