How can i decide or understand whether any statement or expression has left to right or right to left associativity?
+3
A:
=, +=, etc, operators that have '=' in them, is right associated.
All others are left-associated.
Pavel Radzivilovsky
2010-06-24 17:24:13
This seems to disagree. http://www.difranco.net/cop2220/op-prec.htm
GMan
2010-06-24 17:28:43
Perhaps I miss something, but I don't know how in any of the unary or ternary operators the associativity is relevant.... Well, I accept your claim anyway,
Pavel Radzivilovsky
2010-06-24 17:33:52
+2
A:
Here's a table of C++ operator precedence.
The operator precedence and associativity are the same in C and C++ (modulo operators that don't exist in the former).
Cogwheel - Matthew Orlando
2010-06-24 17:24:38
Aren't the precedence and associativity the same (modulo operators that don't exist in C)?
Cogwheel - Matthew Orlando
2010-06-24 17:32:01
http://en.wikipedia.org/wiki/Operators_in_C_and_C%2B%2B#Operator_precedence
Cogwheel - Matthew Orlando
2010-06-24 17:35:30
@Cogwhere: They are, but a user at a level that they need to ask about precedence can't be guaranteed to know that, so the answer should *say* as much or link to a c specific reference. But in any case, bare links are rotten SO answers. At a minimum summarize what's to be found on the other end.
dmckee
2010-06-24 17:40:22
@dmckee Thanks for the feedback. I've edited the post.
Cogwheel - Matthew Orlando
2010-06-24 17:41:36
This is not helpful or constructive. By way of reference, note that Joel himself wrote ["How do I move the turtle in LOGO?"](http://stackoverflow.com/questions/1003841/how-do-i-move-the-turtle-in-logo) to emphasize that no question is too basic.
dmckee
2010-06-24 17:46:54
A:
Read the standards
EDITED: I don't have the standards myself, but I've found this link supposed to be based on the standard.
Also, qoting Kernigham & Ritchie:
Arithmetic operators associate left to right.
Expressions connected by && or || are evaluated left to right, and evaluation stops as soon as the truth or falsehood of the result is known. Most C programs rely on these properties.
Operators Associativity
() [] -> . left to right
! ~ ++ -- + - * (type) sizeof right to left
* / % left to right
+ - left to right
<< >> left to right
< <= > >= left to right
== != left to right
& left to right
^ left to right
| left to right
&& left to right
|| left to right
?: right to left
= += -= *= /= %= &= ^= |= <<= >>= right to left
, left to right
Unary & +, -, and * have higher precedence than the binary forms.
pcent
2010-06-24 17:49:53