经常看到静态扩展使用 math 库。这个代码展示一个简单的例子： ~~~ class MathStaticExtension { /* Converts an angle in radians to degrees */ inline public static function toDegrees(radians:Float):Float { return radians * 180 / Math.PI; } } ~~~ ~~~ using MathStaticExtension; class Main { public static function main() { var ang = 1/2*Math.PI; trace(ang.toDegrees()); //90 } } ~~~