ternary-operator

I need to set value to a that depends on a condition. What is the shortest way to do this with CoffeeScript? E.g. this is how I'd do it in JavaScript: a = true ? 5 : 10 # => a = 5 a = false ? 5 : 10 # => a = 10 Since everything is an expression, and thus results in a value, you can just use if/else . a = if true then 5 else 10 a = if false then 5 else 10 You can see more about expression examples here . a = if true then 5 else 10 a = if false then 5 else 10 See documentation . In almost any language this should work instead: a = true && 5 || 10 a = false && 5 || 10 Coffeescript doesn't support

Can someone tell me why this use of the ternary operator is incorrect? Operands 2 and 3 return a boolean. public class Something { ... private static final double REFERENCE_FRAME_MID_X = 0; private static final double REFERENCE_FRAME_MID_Y = 0; private boolean findInsideOrOutsideGeneralEllipse(Point2D destCirclePos) { List<Boolean> returnValue = new ArrayList<>(); Point2D referenceFrameCenter = new Point2D.Double(REFERENCE_FRAME_MID_X, REFERENCE_FRAME_MID_Y); Ellipse2D insideAreaEllipse2D = getEllipse2D(referenceFrameCenter.getX(), referenceFrameCenter.getY(), destCirclePos.distance

I am attempting to create a ternary expression and I am getting the following error "Type of conditional expression cannot be determined because there is no implicit conversion between LiveSubscription and DisconnectedSubscription" The same logic works in an if statement, but I wanted to understand why it won't work in a ternary expression - Here is the gist of what I am trying to do: public interface IClientSubscription { bool TryDisconnect(); } public class LiveSubscription : IClientSubscription { public bool TryDisconnect() { return true; } } public class DisconnectedSubscription :

Can someone explain why this code? Collection c = (5 == 5) ? new ArrayList() : new HashSet(); produces the following compiler error: Incompatible conditional operand types ArrayList and HashSet For reasons that I don't understand, the following fixes the problem Collection c = (5 == 5) ? (Collection) new ArrayList() : new HashSet(); I'm using Java 1.4. This was a bug in 1.4 and has been fixed according bugreport 5080917 . Evaluation This is a bug. xxxxx@xxxxx 2004-07-30 Daniel more or less gets this right, but has deleted his answer (with five up votes). Relevant quote from 2nd Ed JLS (1.2-1.4

Can this be done in JavaScript? type == 1 ? function1() : function2(); Yes, that's valid code. It will invoke either function1() or function2() , but not both - depending on the value of type . It won't invoke two functions. It will invoke one of your two functions. 来源： https://stackoverflow.com/questions/1655037/using-ternary-operator-in-javascript-to-invoke-two-functions

The following tag of JSTL can be used to set a value to a variable in a request scope. <c:set var="value" scope="request" value="someValue"/> I want to check conditionally, if the variable value being set is empty or not and display the result accordingly something like the following, using <c:when>...</c:when> . <c:choose> <c:when test="${not empty value}"> <c:out default="None" value="${value}"/> </c:when> <c:otherwise> <c:out default="None" value="None"/> </c:otherwise> </c:choose> I want to reduce the line of code using a ternary expression like, <c:out default="None" value="${not empty

What's wrong with this code: void bark(boolean hamlet) { hamlet ? System.out.println("To Bark.") : System.out.println("Not to Bark"); } Ternary operators can't have statements that don't return values, void methods. You need statements that have return values. You need to rewrite it. void bark(boolean hamlet) { System.out.println( hamlet ? "To Bark." : "Not to Bark" ); } You can read why in the Java Language Specification, 15.25. Conditional Operator ? : It is a compile-time error for either the second or the third operand expression to be an invocation of a void method. You need to do as