= and ==

Or

:= and =

?

what the duck is :=
it's the ugliest thing I've encountered so far

@Minzkraut assignment!

Pascal assignment sux! (:=)

C rules:

if(a=1)
{
}

@JohanO a==1 surely?

@spl0 uh no then it wouldnt be an assignment, right?

@JohanO ya but a=1 doesn't make much sense in an if statement?

@spl0
I'm sure its if [a ≡ 1]

<- and =

@youness Cool :-)

What language uses <- for assignment?

@spl0 in fsharp, ocaml, haskell but its not realy an assignment

@youness thank you!

@spl0 you can do assingnments in a condition.

if(a = 1) is the equivalent of:

a = 1;
if(a)

Not that it's very useful in this case :)

@freakbyte yep, that was my point really :)

@spl0 I think R also uses <-

@freakbyte isn't instead if the assignement was successful? In c++, the assignement operator usually returns a reference to the "assigned to" variable, which is then evaluated. Don't know if c is the same...

===

@Andlat Can you give us an example?

@zourtney does anything really use === ?

@spl0 In Javascript it's generally considered best practice

@mclark1129 Thanks! Never used JavaScript!

@freakbyte exactly my point, C lets you do assignment and condition in one statement

@spl0 (a = 1) == &a and since &a != false ( or null) , the condition is evaluated to true. It might return something else if the assignment wasn't successful

@Andlat errr. don't understand that sorry!

a=1 will always evaluate to 1.

So if evaluated in the context of a condition it will always be true.

&a is the address of the variable a isn't it? That will not be 1. So, (a=1) != &a

@spl0 In c++, the assignement operator = usually returns a reference if it was successful. So a = 1 returns &a and that is what is evaluated in the condition. I learned that from c++ primer and have been using it like this for years, but I might have misunderstood. I'll do some tests later.

@Andlat

$ cat z.C
#include <iostream>
main()
{
int a;
std::cout << (a=1) << "\n" << &a << "\n";
}
$ g++ -o z z.C
$ ./z
1
0x7ffff5ab1c1c
$

@spl0 your code prints the value of ++a. Here's a link on a stackoverflow question explaining the return value: http://stackoverflow.com/questions/...

@Andlat yep just showing they weren't equal...!

Sorry if I misunderstood!