ActionScript: The Definitive Guide

Simulating the switch Statement

Though switch statements (sometimes called case statements) are not supported by ActionScript, this common form of complex conditional can be emulated. A switch statement lets us execute only one of a series of possible code blocks based on the value of a single test expression. For example, in the following JavaScript switch statement, we greet the user with a custom message depending on the value of the test expression gender:

var surname = "Porter";
var gender = "male";

switch (gender) {   
  case "femaleMarried" :       
    alert("Hello Mrs. " + surname);       
    break;    
  case "femaleGeneric" :      
    alert("Hello Ms. " + surname);  
    break;   
  case "male" :       
    alert("Hello Mr. " + surname);      
    break;    
  default :      
    alert("Hello " + surname); 
}

In the JavaScript example, switch attempts to match the value of gender to one of the case expressions: “femaleMarried”, “femaleGeneric”, or “male”. Because gender matches the expression “male”, the substatement alert(“Hello Mr. " + surname); is executed. If the test expression had not matched any case, then the default statement—alert(“Hello " + surname);—would have been executed.

In ActionScript, we can simulate a switch statement using a chain of if-else if-else statements, like this:

var surname = "Porter"; var gender = "male"; if (gender == "femaleMarried") { trace("Hello Mrs. " + surname); } else if (gender == "femaleGeneric") { trace("Hello Ms. " + surname); } else if (gender == "male") { trace("Hello Mr. " + surname); } else { trace("Hello " + surname); ...