variable-assignment

I'm looking through some old Fortran 90 code and have come across the => symbol: var => item It looks like it's being used for some sort of assignment. Searching Google for "arrow symbol Fortran" or "equals greater than symbol Fortran" gives me no related material. => appears in six contexts as a syntactic element in modern Fortran, many, but not all, related to pointers: pointer assignment ; pointer initialization ; procedure (pointer) declaration ; type-bound procedure declaration ; association ; renaming . There is close connection between most of these. Loosely, in many => can be viewed as

Possible Duplicate: are arrays in php passed by value or by reference? I heard that PHP can select how to assign arrays, depends on array size. It can assign by copying value (as any scalar type) or by reference. PHP always assign array to variables by copying a value, as it says in manual. Or it can assign by reference. ? <?php $a = array(1,2,3); ?> Michael Berkowski Assigning arrays by reference is possible when assigning array variables to other variables: // By value... $a = array(1,2,3); $b = $a; array_push($a, 5); print_r($b); // $b is not a reference to $a Array ( [0] => 1 [1] => 2 [2]

A simple question about Python syntax. I want to assign a value from a function to a variable during the condition for a while loop. When the value returned from the function is false, the loop should break. I know how to do it in PHP. while (($data = fgetcsv($fh, 1000, ",")) !== FALSE) However when I try a similar syntax in Python I get a syntax error. You cannot use assignment in an expression. Assignment is itself a statement, and you cannot combine Python statements. This is an explicit choice made by the language designers; it is all too easy to accidentally use one = and assign, where

I don't know what to search to find an explanation for this, so I am asking. I have this code which reports error: struct Settings{ int width; int height; } settings; settings.width = 800; // 'settings' does not name a type error settings.height = 600; // 'settings' does not name a type error int main(){ cout << settings.width << " " << settings.height << endl; but if I put the value assignment in main, it works: struct Settings{ int width; int height; } settings; main () { settings.width = 800; // no error settings.height = 600; // no error Can you explain me why? EDIT: Regarding to Ralph

int a, b, n; ... (a, b) = (2, 3); // 'a' is now 2 and 'b' is now 3 This sort of thing would be really helpfull in C#. In this example 'a' and 'b' arn't encapsulated together such as the X and Y of a position might be. Does this exist in some form? Below is a less trivial example. (a, b) = n == 4 ? (2, 3) : (3, n % 2 == 0 ? 1 : 2); Adam Maras shows in the comments that: var result = n == 4 ? Tuple.Create(2, 3) : Tuple.Create(3, n % 2 == 0 ? 1 : 2); Sort of works for the example above however as he then points out it creates a new truple instead of changing the specified values. Eric Lippert

Eclipse will give an error, "The left-hand side of an assignment must be a variable", when I try something like: public class Thing{ String a1; int a2; public void meth(){ Thing A = new Thing(); this = A; } } I had to assign each variable ( this.a1 = A.a1; this.a2 = A.a2; ) as a work around. Are there other ways to do this without going through each variable field? And if this is not a variable what is it called? this is a pseudo-variable that points to the current instance of the object, it can not be reassigned. It's also considered a keyword in the language, according to section §3.9 of the

I was recently looking into internals of CancellationToken structure and discovered a bit of weird construct (to be more precise, assignment of value to this keyword). Code of one of its constructors is as following: public CancellationToken( bool canceled ) { this = new CancellationToken(); if ( canceled ) { this.m_source = CancellationTokenSource.InternalGetStaticSource( canceled ); } } What is the meaning of line on which the assignment to this keyword occurs? Please note that assignment to this keyword is not possible for classes - error Cannot assign to '<this>' because it is read-only