operator-keyword

问题 I stumbled across this post where user chepner proposed in his answer the usage of \j (as mentioned in the bash manual) to retrieve the current running count of background jobs. Basically it boils down to num_jobs="\j" echo ${num_jobs@P} Can anyone enlighten me on what is going on here exactly? E.g. why ${\j@P} is not working and what @P is doing exactly? 回答1: Like any parameter expansion, you have to supply the name of a parameter, not an arbitrary string. \j isn't the name of a parameter;

问题 Given the the below two statements, could someone help me use only the ternary operator instead of if statements? I have tried a lot to do that: if(strstr(cv[i],a.c_str())) { o=1; p=cv[i]; p=p.substr(a.size()+1); } else o+=4; if (b^*s && c++ + 1 ^ *s) { cout << b; if (b^--c) cout << (c - b>1 ? "-" : ",") << c; if (a) cout << ","; b = c = *s; } 回答1: The ternary operator is an expression, which returns a value when evaluated: <result> = <condition> ? <when true> : <when false> In this pseudo

问题 This is a follow-up question to this answer. I am trying to build a loop that produces a set of three random numbers until they match a particular pre-defined set of three arbitrary chosen numbers. I'm still trying to figure out what operators to use for the program to accept the random numbers in any order but without any results. I tried to your !(first==one && second==two && third==three) but it doesn't seem to work in c++. Thanks for your answer. 回答1: The condition that you tried implies

问题 I need to add "Uhr" at the end of the following Code: <? $doc = JFactory::getDocument(); $doc->setTitle($event->title . " | Example"); $doc->setDescription($event->title . " am " . $event->start, 'end' -> $event->end "uhr needs to be here"); ?> how can I archive this? Because if I add a . "Uhr" it doesn't work :( 回答1: $doc->setDescription($event->title . " am " . $event->start . ", " . $event->end . " Uhr"); should do it. Formatted dates: $doc->setDescription($event->title . " am " . date('d

问题 Poco items are wrapped. abstract class AbstractPocoUI<T> { protected T PocoItem; } class PocoA { } class PocoAUI:AbstractPocoUI<PocoA> { } I want to do something like this var c = new ObservableCollection<PocoAUI>(collectionOfTypePocoA.Cast<PocoAUI>()); How can i override cast operator in abstract class? What should i do in AbstractPocoUI to get for example PocoAUI with PocoA in PocoItem field ? Thanks. 回答1: You can implement IConvertible interface or create a TypeConverter but casting cannot

问题 Is there a way to abbreviate the following type of condition in Swift? if ( (myEnum == .1 || myEnum == .2 || myEnum == .3 || myEnum == .8) && startButton.isSelected ) I tried typing: if ( (myEnum == .1 || .2 || .3 || .8) && startButton.isSelected ) and: if ( (myEnum == .1,.2,.3,.8) && startButton.isSelected ) but none of those worked. I also tried looking at documentation but can't find a similar example. Thanks! 回答1: I don't think there is a way to abbreviate it like you want but there is,

问题 I'm currently converting and casting from Class to Class2 using the implicit operator. But what I want to do is, that, whenever I refer to foo (Class<Class2>) , I'd like for Goo(Class) to be returned so that I can access the public Properties of it directly, without having to cast it first into a new variable. In other words, I want that when I access Class<Class> , I'd like Goo to be returned. I'm aware I might have not been able to explain properly so feel free to ask in the comment section

问题 I need to compare a value from an array with a list of possible results, and then return a value in a variable depending on whether the list is matched or not. i.e. I have an array called $ErroredBackup with a column "status" I need to compare each $ErroredBackup.Status with a list of possible numbers, and if it matches set a $output variable to Error. If it doesn't match, leave the $output variable as is (I set it to Pass to start with) I've tried using -contain , but that seems to be the

问题 the std::array im getting no match for ‘operator=’ in ‘myarr = {1, 5, 2, 3, 4}’ error when compiling this code #include <iostream> #include <array> using namespace std; int main(int argc, char const *argv[]) { array<int, 5> myarr; myarr = {1,5,2,3,4}; for(auto i : myarr) { cout << i << endl; } return 0; } but it compiles when i do it on the same line array<int, 5> myarr = {1,5,2,3,4}; how to assign values on the seprate line i need to assign values in the class constructor how can i do it ?

问题 I am trying to make a program generating random numbers until it finds a predefined set of numbers (eg. if I had a set of my 5 favourite numbers, how many times would I need to play for the computer to randomly find the same numbers). I have written a simple program but don't understand the outcome which seems to be slightly unrelated to what I expected, for example the outcome does not necessarily contain all of the predefined numbers sometimes it does (and even that doesn't stop the loop