In languages such as C, C++, C#, Java, IF is a statement implemented as a reserved word, part of the core of the language. In programming languages of the LISP family (Scheme comes to mind) IF is an expression (meaning that it returns a value) and is implemented as a special form. On the other … Read more
Type traits: #include <iostream> #include <type_traits> // C++0x //#include <tr1/type_traits> // C++03, use std::tr1 template<typename T> void printType(T param) { if(std::is_same<T,char*>::value) std::cout << “char*” << endl; else if(std::is_same<T,int>::value) std::cout << “int” << endl; else std::cout << “???” << endl; } Or even better yet, just overload the function: template<class T> void printType(T partam){ std::cout << … Read more
No–the second condition won’t always be executed (which makes your examples equivalent). PHP’s &&, ||, and, and or operators are implemented as “short-circuit” operators. As soon as a condition is found that forces the result for the overall conditional, evaluation of subsequent conditions stops. From http://www.php.net/manual/en/language.operators.logical.php // ——————– // foo() will never get called as … Read more
This is the conditional operator. $x ? $y : $z means “if $x is true, then use $y; otherwise use $z“. It also has a short form. $x ?: $z means “if $x is true, then use $x; otherwise use $z“. People will tell you that ?: is “the ternary operator”. This is wrong. ?: … Read more
Here’s how I usually do it: Just replace your query with this statement SELECT * FROM table WHERE 1 SELECT CASE WHEN EXISTS ( SELECT * FROM table WHERE 1 ) THEN ‘TRUE’ ELSE ‘FALSE’ END
Well, I can think of a few ways: essentially blow up the dataframe by just merging on the exact field (company)… then filter on the 30-day windows after the merge. should be fast but could use lots of memory Move the merging and filtering on the 30-day window into a groupby(). results in a merge … Read more
The other answers that Comparison takes place before Boolean are 100% correct. As an alternative (for situations like what you’ve demonstrated) you can also use this as a way to combine the conditions: if socket.gethostname() in (‘bristle’, ‘rete’): # Something here that operates under the conditions. That saves you the separate calls to socket.gethostname and … Read more
The && and || operators short-circuit. That is: 1) If && evaluates its first operand as false, it does not evaluate its second operand. 2) If || evaluates its first operand as true, it does not evaluate its second operand. This lets you do null check && do something with object, as if it is … Read more
Just remove the .val(). Like: if ( $(‘html’).attr(‘lang’) == ‘fr-FR’ ) { // do this } else { // do that }