The difference is static typing of the expressions at compile time: Summary E1: `(false ? 1.0f : null)` – arg 2 ‘1.0f’ : type float, – arg 3 ‘null’ : type null – therefore operator ?: : type Float (see explanation below) – therefore autobox arg2 – therefore autobox arg3 E2: `(false ? 1.0f : … Read more
Rust does not have the ternary operator because it’s not needed. Almost everything evaluates to some value, and if / else expressions are no exception: let r = 42.42; let sgn_r = if r >= 0. { 1. } else { -1. }; You’ll note that I’ve also changed your variable names to be idiomatic … Read more
That’s just horrible code. It’s badly formatted. I don’t see the hierarchy of the expression. Even if it had good formatting, the expression would be way too complex to quickly parse with the human eye. The intention is unclear. What’s the purpose of those conditions? So what can you do? Use conditional statements (if). Extract … Read more
The performance difference is negligible. The && operator won’t check the right hand expression when the left hand expression evaluates false. However, the & operator will check both regardless, maybe your confusion is caused by this fact. In this particular example, I’d just choose the one using &&, since that’s better readable.
It works like this: (condition) ? true-clause : false-clause It’s most commonly used in assignment operations, although it has other uses as well. The ternary operator ? is a way of shortening an if-else clause, and is also called an immediate-if statement in other languages (IIf(condition,true-clause,false-clause) in VB, for example). For example: bool Three = … Read more
Performance The ternary operator shouldn’t differ in performance from a well-written equivalent if/else statement… they may well resolve to the same representation in the Abstract Syntax Tree, undergo the same optimisations etc.. Things you can only do with ? : If you’re initialising a constant or reference, or working out which value to use inside … Read more
This is explained in the Perl documentation. Because of Perl operator precedence the statement is being parsed as ($condition ? $a= 2 : $a ) = 3 ; Because the ?: operator produces an assignable result, 3 is assigned to the result of the condition. When $condition is true this means ($a=2)=3 giving $a=3 When … Read more
The null coalesce operator is much clearer when checking for null, that is its main purpose. It can also be chained. object a = null; object b = null; object c = new object(); object d = a ?? b ?? c; //d == c. While that operator is limited to null checking, the ternary … Read more
UPDATE: This question was the subject of my blog on May 27th 2010. Thanks for the great question! There are a great many very confusing answers here. Let me try to precisely answer your question. Let’s simplify this down: object value = whatever; bool condition = something; decimal result = (decimal)(condition ? value : 0); … Read more
Elvis ?: returns the first argument if it contains a “true-ish” value (see which values are considered loosely equal to true in the first line of the Loose comparisons with == table). Or the second argument otherwise $result = $var ?: ‘default’; // is a shorthand for $result = $var ? $var : ‘default’; Null … Read more