I'm failing to understand exactly what the IF statement is doing, from what I can see it is checking if the variable x is equal to the int 0. If this is true the ABSOLUTE value of the variable y is returned... this is when I lose the plot, why would the return statement then go on to include <= ESPILON? Surely this means less than or equ...
I'm having an issue with expressions within reports. I'm coloring the background of a textbox within a table depending on the value within it. The text in the field relates to backups for a SQL Server. The value is either a date or the text "Not Yet Taken". If the date is more than 2 days old, I want the background to be yellow. If ...
Okay, I'm aware that the standard dictates that a C++ implementation may choose in which order arguments of a function are evaluated, but are there any implementations that actually 'take advantage' of this in a scenario where it would actually affect the program? Classic Example: int i = 0; foo(i++, i++); Thanks. Note: I'm not look...
Consider this example: struct { int num; } s, *ps; s.num = 0; ps = &s; ++ps->num; printf("%d", s.num); /* Prints 1 */ It prints 1. So I understand that it is because according to operators precedence, -> is higher than ++, so the value ps->num (which is 0) is firstly fetched and then the ++ operator operates on it, so it incre...
I wanted to make a lazy list in Scheme. This is what I have so far. ;; Constructor for Pairs (define (cons-stream a b) (cons a (λ() b))) ;; Selectors (define (car-stream a-stream) (car a-stream)) (define (cdr-stream a-stream) ((cdr a-stream))) ;; Lazy List using the pairs (define (lazy-list from) (cons-stream from (lazy-list ...
So, the C++ standard requires that class members be initialized in the order in which they are declared in the class, rather than the order that they're mentioned in any constructor's initializer list. However, this doesn't imply anything about the order in which the arguments to those initializations are evaluated. I'm working with a sy...
Which order is the and && operator evaluated For example the following code if (int alpha = value1-value2 && alpha > 0.001) //do something threw an exception that alpha is being used without being initiated. I thought the expression left of the && would always initiate the value of alpha first, but it seems I may be wrong Any id...
What is the order of evaluation in the following query: UPDATE tbl SET q = q + 1, p = q; That is, will "tbl"."p" be set to q or q + 1? Is order of evaluation here governed by SQL standard? Thanks. UPDATE After considering Migs' answer, I ran some tests on all DBs I could find. While I don't know what the standard says, implementa...
look at the following simple code: #include <iostream> #include <string> using namespace std; int main() { string s("1234567890"); string::iterator i1 = s.begin(); string::iterator i2 = s.begin(); string s1, s2; s1.append(i1, ++i1); s2.append(++i2, s.end()); cout << s1 << endl; cout << s2 << endl; } w...
In Oracle, which clause types get evaluated first? If I had the following ( pretend .... represent valid expressions and relation names ), what would the order of evaluation be? SELECT ... FROM ..... WHERE ........ GROUP BY ........... HAVING ............. ORDER BY ................ I am under the impression that the SELECT ...
Uu[z_,x_,t_] := A1[z]*F[t*a*x] Wu[z_,x_,t_] := B1[z]*F[t*a*x] Pu[z_,x_,t_] := C1[z]*F[t*a*x] eq1 = D[Uu[z,x,t],t]==-R*D[Pu[z,x,t],x]; C1z = DSolve[eq1,C1[z],z]; eq2 = D[Wu[z,x,t],t]==-R*D[Pu[z,x,t],z]/.C1z[[1]] The assignment /.C1z[[1]] does not behave the way I expect it to. I am unsure of even what this pheonomena is called, (which ...
I am using Coverity on a project to find errors. It reports an error for this expression (The variable names are of course changed): x= (a>= b) ? ++x: 0; The message is: EVALUATION_ORDER defect: In "x=(a>= b) ? ++x: 0;", "x" is written in "x" (the assignment LHS) and written in "(a>= b) ? ++x: 0;" but the order in which the...
The following procedure is valid in both scheme r6rs and Racket: ;; create a list of all the numbers from 1 to n (define (make-nums n) (do [(x n (- x 1)) (lst (list) (cons x lst))] ((= x 0) lst))) I've tested it for both r6rs and Racket and it does work properly, but I only know that for sure for DrRacket. My question is i...
The output of the following code is "321" without quotes. Why not "123"? #include <iostream> using namespace std; int& inc(int& start) { return ++start; } int main() { int i = 0; cout << inc(i) << inc(i) << inc(i) << endl; } ...