Python has such an operator: variable = something if condition else something_else Alternatively, although not recommended (see karadoc’s comment): variable = (condition and something) or something_else
Well, here’s what a note in the C++11 standard, [dcl.init.list] p1 says: List-initialization can be used as the initializer in a variable definition ([dcl.init]) as the initializer in a new expression ([expr.new]) in a return statement ([stmt.return]) as a function argument ([expr.call]) as a subscript ([expr.sub]) as an argument to a constructor invocation ([dcl.init], [expr.type.conv]) … Read more
The relevant section of the C# 3.0 spec is 7.13, the conditional operator: The second and third operands of the ?: operator control the type of the conditional expression. Let X and Y be the types of the second and third operands. Then, If X and Y are the same type, then this is the … Read more
One problem is that a ternary relational construct would introduce serious parser problems: <expr> ::= <expr> <rel-op> <expr> | … | <expr> <rel-op> <expr> <rel-op> <expr> When you try to express a grammar with those productions using a typical PGS, you’ll find that there is a shift-reduce conflict at the point of the first <rel-op>. … Read more
Such an operator isn’t part of the current Delphi version because it wasn’t part of the previous version, and demand wasn’t great enough to justify the cost of adding it. (You’ll find that explanation applies to lots of features you wish you had in lots of products.) Delphi provides a set of IfThen functions in … Read more
Why not use a switch? I think it’s way more readable. private bool CanExecuteAdd(string parameter) { if (Script == null) return false; switch (parameter) { case “Step”: return true; case “Element”: return ElementSelectedInLibrary != null && SelectedStep != null; case “Choice”: return SelectedElement != null; case “Jump”: return SelectedStep != null; case “Conditional jump”: return … Read more
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
The operator precedence in the C/C++ language in not defined by a table or numbers, but by a grammar. Here is the grammar for conditional operator from C++0x draft chapter 5.16 Conditional operator [expr.cond]: conditional-expression: logical-or-expression logical-or-expression ? expression : assignment-expression The precedence table like this one is therefore correct when you use assignment on … Read more
Well, the ternary operator in Java acts like this… return_value = (true-false condition) ? (if true expression) : (if false expression); …Another way of looking at it… return_value = (true-false condition) ? (if true expression) : (if false expression); You question is kind of vague and we have to assume here. If (and only if) … Read more
Since you wanted the spec, here it is (from ยง15.25 Conditional Operator ? :, the last sentence of the section): The operand expression not chosen is not evaluated for that particular evaluation of the conditional expression.