ternary-operator

问题 I was looking to see if it's possible to set multiple variables with one ternary operator. I google'd a bit, but didn't come up with anything. I started testing a few ideas, and found something close -- but also getting some strange behavior; any ideas as to what's going on? And, is it possible to set more than one var in a single ternary operation? If so, is there a proper way of doing it? $i=9; ($i==9)?($w=3|$r=2):($w=7|$r=1); echo 'w= '.$w.' r= '.$r;//w= 3 r= 2 $i=9; ($i==9)?($w=4|$r=2):(

问题 I'm several hours into building a simple sortable search results for an online merchant site. The way it works, is that a html template is fetched of the search page, while the search is carried out with ajax. the json data is retrieved, and the div elements are then created. I have already completed the sort , per , and direction sorts, but now i'm stuck on the filter sort and i really have no idea where to even begin on this last one. the last sort function needs to iterate over each div,

问题 This question already has answers here : Java ternary operator precedence ? Different outputs given (3 answers) Strange Null pointer exception case: ternary conditional operator not working with string concatenation (6 answers) Closed 4 months ago . I have a difficulty in understanding how the ternary operation works in the below code. public static void main(String[] args) { try{ throw new ArithmeticException("Exception Testing..."); }catch(Exception e){ msg = "First Statement : " + e

问题 I am a novice in C and having the following problem while compiling a simple code: #include <stdio.h> int main() { int i, a, b; i = 3; a = b = 0; printf("Before: "); printf("%d %d\n", a, b); i == 3 ? a = 4 : a = 10; /* Line 9 */ printf("After: "); printf("%d %d\n", a, b); return 0; } Gives me error: #gcc some.c In function ‘main’: some.c:9: error: lvalue required as left operand of assignment I cannot understand it. What am i doing wrong? 回答1: This operator i==3 ? a=4 : a = 10; is equivalent

问题 For some reason my ternary operator assignment isn't work for the second part of my array. Anyone see what I'm doing wrong? Its supposed to just see if there is a value for the permalink field and if there isn't then insert the link_url into the array. function getSiteMap() { $this->db->select('site_menu_structures_links.id, site_menu_structures_links.link_name'); $this->db->from('site_menu_structures_links'); $this->db->where('site_menu_structures_links.status_id', 1); $this->db->where('site

问题 This question is more for my curiosity than anything else. I often employ Java's ternary operator to write shorter code. I have been wondering, however, whether it is possible to use it if one of the if or else conditions are empty. In more details: int x = some_function(); if (x > 0) x--; else x++; can be written as x = (x > 0) ? x-1 : x+1; But is it possible to write if (x > 0) x-1; as a ternary expression with an empty else clause? 回答1: But is it possible to write if (x > 0) x--; as a

问题 This question already has answers here : Nullable types and the ternary operator: why is `? 10 : null` forbidden? [duplicate] (9 answers) Conditional operator cannot cast implicitly? (3 answers) Closed 6 years ago . var dict = new Dictionary<string, object>(); DateTime? myDate; /*Next line gives: Type of conditional expression cannot be determined because there is no implicit conversion between 'System.DateTime?' and 'System.DBNull' */ dict.Add("breakit", myDate.HasValue ? myDate.Value :

问题 const cond = false const extraInfo = [ { a: 11, b: 25 }, { a: 12, b: 34 }, { a: 1, c: 99 } ] const userInfo = [ { z: 8 }, { z: 10 }, ...(cond && extraInfo) ] When cond is true, I want both extra and user info. When cond is false, only userInfo is needed. The issue is when cond is false, I get TypeError: (intermediate value)(intermediate value)(intermediate value)[Symbol.iterator] is not a function My understanding is that I am not allowed to use a boolean as a spread element, in this case ..

问题 Does the ternary operation return a copy or reference? I checked the following code vector<int> v0 = { 1, 2 }; vector<int> v1 = { 3 }; vector<int>& v = true ? v0 : v1; v.clear(); // v0 will be cleared also I think the ternary operation returns a copy of v0 . And then pass it to v . Thus v and v0 has different storage of data. Testing doesn't show it. Thanks, Kerrek SB! I add a "should-not-compiled" example (Thanks WhiZTiM!) to show the point. vector<int>& v = true ? v0 : vector<int>{3}; v

问题 I would like to simplify this: var countA: Int = 0 var countB: Int = 0 if (validItem) { if (region.equalsIgnoreCase( "US" )) { if (itemList > 0) { countB = 1 } else { countA = 1 } } else { countB = 1 } } else { countA = 1 } How do I use ternary operator in scala. 回答1: This might be a bit confusing for a "newbie", but you could attach a ternary method to the Boolean class like so. implicit class Ternary[T](condition: Boolean) { def ??(a: => T, b: => T): T = if (condition) a else b } Usage: (4