Equals and "==" operator

[#Hai]

Hi,
What is the difference between Object.Equals and "==" operator ?
When we use CollectionBase. List.Remove(obj ect), which methods is used to
compare objects ?

Thanks

[Anthony Bouch]

Re: Equals and "==&quo t; operator

For interest, there are also performance differences between instance and
static(shared) methods for Equals and the == operator when comparing
strings.

" #Hai" <ReplyToNewsgro upOnly@Softhome .net> wrote in message
news:ekVeJvVPDH A.1908@TK2MSFTN GP11.phx.gbl...[color=blue]
> Hi,
> What is the difference between Object.Equals and "==" operator ?
> When we use CollectionBase. List.Remove(obj ect), which methods is used to
> compare objects ?
>
> Thanks
>
>[/color]

[Markus Wildgruber]

Re: Equals and &quot;==&quo t; operator

Hi Anthony!

Can you tell me more about the performance differences. Which way is
fastest?

TIA,

Markus

"Anthony Bouch" <tony@nospamfor ever.com> schrieb im Newsbeitrag
news:e2lV4BfPDH A.3192@TK2MSFTN GP10.phx.gbl...[color=blue]
> For interest, there are also performance differences between instance and
> static(shared) methods for Equals and the == operator when comparing
> strings.
>
> " #Hai" <ReplyToNewsgro upOnly@Softhome .net> wrote in message
> news:ekVeJvVPDH A.1908@TK2MSFTN GP11.phx.gbl...[color=green]
> > Hi,
> > What is the difference between Object.Equals and "==" operator ?
> > When we use CollectionBase. List.Remove(obj ect), which methods is used to
> > compare objects ?
> >
> > Thanks
> >
> >[/color]
>
>[/color]

[100]

Re: Equals and &quot;==&quo t; operator

Furthermore, not all languages support operator overloading. So, if one
wants to write language independent code she/he should not rely on operator
overloading. For c# convenince the operators might be overloaded and the
virtual method might be used internally.

B/rgds
100

"Jon Skeet" <skeet@pobox.co m> wrote in message
news:MPG.19677b 53e56b5a99989fb c@news.microsof t.com...[color=blue]
> [What does this have to do with Windows forms, by the way? Please limit
> your post to relevant groups - preferrably only one!]
>
> #Hai <ReplyToNewsgro upOnly@Softhome .net> wrote:[color=green]
> > What is the difference between Object.Equals and "==" operator ?[/color]
>
> Operators are not applied polymorphically , methods are. For instance:
>
> string x = "hello";
> string y = new string (x.ToCharArray( ));
>
> object a=x;
> object b=y;
>
> x==y; // True, because String== is applied
> a==b; // False, because Object== is applied, which asserts reference
> // identity
>
> x.Equals(y); // True, because String.Equals override Object.Equals
> a.Equals(b); // True, because methods are invoked polymorphically
>[color=green]
> > When we use CollectionBase. List.Remove(obj ect), which methods is used to
> > compare objects ?[/color]
>
> Almost certainly Equals - it's the only way that makes sense, really,
> given that CollectionBase only knows about Objects, so to remove
> entries you'd have to have the exact reference if it used ==.
>
> --
> Jon Skeet - <skeet@pobox.co m>
> http://www.pobox.com/~skeet/
> If replying to the group, please do not mail me too[/color]

[code.book]

You can find the answer at

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