Yes, it is a shorthand form of int count; if (isHere) count = getHereCount(index); else count = getAwayCount(index); It’s called the conditional operator. Many people (erroneously) call it the ternary operator, because it’s the only ternary (three-argument) operator in Java, C, C++, and probably many other languages. But theoretically there could be another ternary operator, … Read more
The compiler interprets null as a null reference to an Integer, applies the autoboxing/unboxing rules for the conditional operator (as described in the Java Language Specification, 15.25), and moves happily on. This will generate a NullPointerException at run time, which you can confirm by trying it.
{{ (ability.id in company_abilities) ? ‘selected’ : ” }} The ternary operator is documented under ‘other operators’
Use it for simple expressions only: int a = (b > 10) ? c : d; Don’t chain or nest ternary operators as it hard to read and confusing: int a = b > 10 ? c < 20 ? 50 : 80 : e == 2 ? 4 : 8; Moreover, when using ternary … Read more
Python’s conditional expressions were designed exactly for this sort of use-case: >>> l = [1, 2, 3, 4, 5] >>> [‘yes’ if v == 1 else ‘no’ if v == 2 else ‘idle’ for v in l] [‘yes’, ‘no’, ‘idle’, ‘idle’, ‘idle’]
Expressions don’t have return types, they have a type and – as it’s known in the latest C++ standard – a value category. A conditional expression can be an lvalue or an rvalue. This is its value category. (This is somewhat of a simplification, in C++11 we have lvalues, xvalues and prvalues.) In very broad … Read more
You are running the [ (aka test) command with the argument “false”, not running the command false. Since “false” is a non-empty string, the test command always succeeds. To actually run the command, drop the [ command. if false; then echo “True” else echo “False” fi
x if y else z is the syntax for the expression you’re returning for each element. Thus you need: [ x if x%2 else x*100 for x in range(1, 10) ] The confusion arises from the fact you’re using a filter in the first example, but not in the second. In the second example you’re … Read more
To answer this question, we’ll examine the assembly code produced by the X86 and X64 JITs for each of these cases. X86, if/then 32: foreach (int i in array) 0000007c 33 D2 xor edx,edx 0000007e 83 7E 04 00 cmp dword ptr [esi+4],0 00000082 7E 1C jle 000000A0 00000084 8B 44 96 08 mov eax,dword … Read more
Yes, it’s possible to use inline if-expressions: {{ ‘Update’ if files else ‘Continue’ }}