ternary-operator

问题 is it possible to differ the variable I'm assigning to depending on a condition? The issue I came across is wanting to do this: (bEquipAsSecondary ? currentWeaponOffhand : currentWeaponMainhand) = weaponToSwitchTo; Instead of if (bEquipAsSecondary) { currentWeaponOffhand = weaponToSwitchTo; } else { currentWeaponMainhand = weaponToSwitchTo; } Which results in the following error Error CS0131 The left-hand side of an assignment must be a variable, property or indexer So I was wondering if

问题 I am trying to do the following: <li <?PHP ($this->pageName == 'index' ? ?>class="current"<?PHP : '')?>><a href="">Home</a></li> But it is not working. Is what I'm trying to achieve possible? If so what am I doing wrong? I know it's not hard to put PHP in HTML lol. I was curious if a ternary operator could be used in a way that is similar to: <?PHP if(1 == 1){?> <p>Test</p> <?PHP }?> 回答1: What you have done will only RETURN the value "class='current'". You still will be required to ECHO/PRINT

来源： https://stackoverflow.com/questions/30670964/why-does-using-0-with-the-ternary-operator-return-the-first-value

问题 I want to evaluate a simple ternary operator inside of a string and can't seem to find the correct syntax. My code looks like this: foreach ($this->team_bumpbox as $index=>$member) echo ".... class='{((1) ? abc : def)}'>...."; but I can't seem to get it to work properly. Any ideas on how to implement this? 回答1: You can't do it inside the string, per se. You need to dot-concatenate. Something like this: echo ".... class='" . (1 ? "abc" : "def") . "'>...."; 来源： https://stackoverflow.com

问题 My compiler is the latest VC++ 2013 RC. int f(bool b) { return {}; // OK return b ? 1 : { }; // C2059: syntax error : '{' return b ? 1 : {0}; // C2059: syntax error : '{' return b ? {1} : {0}; // C2059: syntax error : '{' } Why can braced-init-list not be used in ternary operator? Is this behavior defined as ill-formed by the C++ standard, or just a bug of the VC++ compiler? 回答1: Well, here's what the standard says about the braced-init-list (8.5.3.1): List-initialization can be used as the

问题 Consider this piece of code: struct Base { int x; }; struct Bar : Base { int y; }; struct Foo : Base { int z; }; Bar* bar = new Bar; Foo* foo = new Foo; Base* returnBase() { Base* obj = !bar ? foo : bar; return obj; } int main() { returnBase(); return 0; } This doesn't work under Clang or GCC, giving me : error: conditional expression between distinct pointer types ‘Foo*’ and ‘Bar*’ lacks a cast Base* obj = !bar ? foo : bar; Which means for it to compile I have to change the code to : Base*

问题 So there is a problem with this, but i'm blind to it. Even after reading the documentation twice (PHP Comparison Operators) isset($items['blog']) ? unset($items['blog']) : NULL; Parse error: syntax error, unexpected T_UNSET 回答1: A @Bryan points out, no function calls to language constructs within the ternary operator. Since there's no return value involved at all here though, just do: unset($items['blog']); There's no need to check if the value is set or not beforehand. If it is not, unset

问题 how to use ternary if else with two or more condition using "OR" and "AND" like if(foo == 1 || foo == 2) { do something } { else do something } i want to use it like foo == 1 || foo == 2 ? doSomething : doSomething 回答1: If you're referring to else if statements in dart, then this ternary operator: (foo==1)?something1():(foo==2)? something2():(foo==3)? something3(): something4(); is equivalent to this: if(foo ==1){ something1(); } elseif(foo ==2){ something2(); } elseif(foo ==3){ something3();

问题 how to use ternary if else with two or more condition using "OR" and "AND" like if(foo == 1 || foo == 2) { do something } { else do something } i want to use it like foo == 1 || foo == 2 ? doSomething : doSomething 回答1: If you're referring to else if statements in dart, then this ternary operator: (foo==1)?something1():(foo==2)? something2():(foo==3)? something3(): something4(); is equivalent to this: if(foo ==1){ something1(); } elseif(foo ==2){ something2(); } elseif(foo ==3){ something3();

问题 how to use ternary if else with two or more condition using "OR" and "AND" like if(foo == 1 || foo == 2) { do something } { else do something } i want to use it like foo == 1 || foo == 2 ? doSomething : doSomething 回答1: If you're referring to else if statements in dart, then this ternary operator: (foo==1)?something1():(foo==2)? something2():(foo==3)? something3(): something4(); is equivalent to this: if(foo ==1){ something1(); } elseif(foo ==2){ something2(); } elseif(foo ==3){ something3();