Title here
Summary here
Recursion in ActionScript
Our example demonstrates recursive functions in ActionScript. Here’s a classic example of calculating factorials recursively.
package {
import flash.display.Sprite;
import flash.text.TextField;
public class Recursion extends Sprite {
public function Recursion() {
var output:TextField = new TextField();
output.width = 400;
output.height = 300;
addChild(output);
// This fact function calls itself until it reaches the
// base case of fact(0).
function fact(n:int):int {
if (n == 0) {
return 1;
}
return n * fact(n-1);
}
output.text += "Factorial of 7: " + fact(7) + "\n";
// Closures can also be recursive in ActionScript
var fib:Function = function(n:int):int {
if (n < 2) {
return n;
}
// Since fib was previously declared, ActionScript
// knows which function to call with fib here.
return fib(n-1) + fib(n-2);
};
output.text += "Fibonacci of 7: " + fib(7);
}
}
}This ActionScript code defines a class Recursion that extends Sprite. In the constructor, we create a TextField to display our output.
We define a recursive fact function to calculate factorials. This function calls itself until it reaches the base case of fact(0).
We then demonstrate the use of a recursive closure with the Fibonacci sequence. In ActionScript, closures can be recursive without any special declaration.
To run this code, you would typically compile it into a SWF file and run it in a Flash Player or AIR runtime environment. The output would be:
Factorial of 7: 5040
Fibonacci of 7: 13This example showcases how ActionScript supports recursive functions and closures, providing a powerful tool for solving problems that have a naturally recursive structure.