Switch (true) with dynamic cases in coldfusion?

Question

To avoid nested if statements and improve readability, I wanted to create switch(true){ ... } in Coldfusion. I often used this in php, but when I try this in Coldfusion, I get the following error on initialization:

Template Error

This expression must have a constant meaning.

This happens when a variable in its state is used in the case of a switch, for example:

 //this example throws the error switch(true){ case foo == 1: writeOutput('foo is 1'); break; } 

Using the switch (true) {...} operator with constant values ​​(as the error explains) works:

 //this example doesn't throw the error switch(true){ case 1 == 1: writeOutput('1 is 1'); break; } 

Is there a way to get the first statement to work in Coldfusion? Maybe with evaluating a variable or some tricks, or is it definitely not going to Coldfusion?

Answer 1

In short: no. The case value must be something that can be compiled with a constant value. 1==1 can be as simple as true . foo == 1 cannot be, since foo is only available at run time.

basically what you are describing is an if / else if / else , so just use one of them.

Answer 2

As Adam and Lee pointed out, the meaning of the case must be constant. I'm not sure what your actual use case is, but you can do something like this:

 switch(foo){ case 1: writeOutput('foo is 1'); break; case 2: writeOutput('foo is 2'); break; case 3: writeOutput('foo is 3'); break; case 4: case 5: case 6: writeOutput('foo is 4 or 5 or 6'); break; default: writeOutput("I do not have a case to handle this value: #foo#"); }