conditional-operator

When stepping through a sqlite3_stmt , I'd like to check against a return value of NULL rather than store it and check against the stored value. Here's what I'm doing now: char *email = (char *)sqlite3_column_text(statement, 10); if (email == NULL) email = ""; And here is what I'd like to be doing, minus the double-call to column : char *email = ((char *)sqlite3_column_text(statement, 10)) ? (char *)sqlite3_column_text(statement, 10) : ""; Is there some way to express the second expression more concisely? I have to do a lot of these repetitively, so I'm looking for brevity. I know this is a

There is an error. Is it wrong to assign a value to a[i] in the following code? Or something is wrong with conditional operators? #include<stdio.h> #include<string.h> int main(){ char a[12]="sumit tyagi"; int i=0; while(a[i]!='\0'){ a[i]>90 ? a[i]=a[i]-32 : a[i]=a[i]+32; //error in this line i++; } printf("\n %s",a); a[i]>90 ? a[i]=a[i]-32 : a[i]=a[i]+32; is not evaluated as a[i]>90 ? (a[i]=a[i]-32) : (a[i]=a[i]+32); since = has lower precedence than ?: . In standard C you can't write it as above although some compilers allow it as an extension. You could write it as the more readable (and

I'm used to write render optional Components like this: var Foo = React.createClass({ render: function() { var length = 0; return <div>Foo {length && <Bar />}</div>; } }); This shorthand if is mentioned in the if/else in JSX guide as immediately-invoked function expression. However, since my latest update of React, it started to render 0 instead of null . Here is a jsfiddle Why is that happening? The && operator evaluates the left-hand expression first, and if the left-hand expression evaluates to something falsy it returns the value of the left-hand expression without evaluating further. So

return true ? 'a' : false ? 'b' : 'c'; This should return 'a', but it doesn't. It returns 'b' instead. Is there a bug in PHP's order of handling the different parts of the conditional operators? I got the idea from Are multiple conditional operators in this situation a good idea? where it does seem to work correctly. (the true and false are for the purpose of the example, of course. in the real code they are statements that evaluate to true and false respectively. yes, i know that for sure) It is recommended that you avoid "stacking" ternary expressions. PHP's behaviour when using more than

I get the following: puts true or true and false # >> true whereas I also get: if true or true and false puts "that's true!" else puts "that's false!" end # >> that's false! Why is true or true and false both true and false (like Schrödinger's cat)? It has to do with precedence. puts true or true and false actually evaluates as (puts true) or (true and false) [EDIT: Not exactly. See the note from Todd below.] , and if true or true and false evaluates as if (true or (true and false)) . This is due to the precedences of puts (a method) and if (a language keyword) relative to the other terms of

Given two implementations of Comparison methods: // compares by Key... private static int CompareByKey(KeyValuePair<int, string> x, KeyValuePair<int, string> y) { return x.Key.CompareTo(y.Key); } // compares by Value... private static int CompareByValue(KeyValuePair<int, string> x, KeyValuePair<int, string> y) { return x.Value.CompareTo(y.Value); } Why wouldn't the following conditional operator code block compile: Comparison<KeyValuePair<int, string>> sortMethod; sortMethod = isSortByActualValue ? CompareByKey : CompareByValue; Compiler error: "Type of conditional expression cannot be

I have a <div> block which I need to set to display:none or display:block based on the condition. The html looks like this, <div style="display:none;"> //some html block content </div> I've tried the following code in thymeleaf, <div th:style="${condition} == 'MATCH' ? display:block : display:none"> //some html block content </div> But the above expression is not working. throws org.thymeleaf.exceptions.TemplateProcessingException: Could not parse as expression: error message. I can do th:classappend to set some class and make this work but want to know if elvis/ternary operator will support