While JavaScript does not explicitly have the enum keyword, you can work around it using JS rich objects to get the functional equivalent. Here's a minimalist example that defines the enum, passes it in as a parameter, and then checks for it in a switch-case statement. Although, this doesn't throw a "compile time" exception if you pass in an invalid value. var Enum_Colors =
{
Red:0,
Blue:1,
Green:2,
Yellow:3
};
function DoStuff()
{
TestEnum(Enum_Colors.Green);
}
function DoError()
{
TestEnum(Enum_Colors.Unknown); //Bad
}
function TestEnum(objColorEnum)
{
var str;
switch(objColorEnum)
{
case Enum_Colors.Red:
str = "red";
break;
case Enum_Colors.Blue:
str = "blue";
break;
case Enum_Colors.Green:
str = "green";
break;
case Enum_Colors.Yellow:
str = "yellow";
break;
default:
str = "none";
break;
}
alert("The enum passed in is: " + str);
}
Thanks to VS2008, you at least get JS intellisence on the "Enum_Colors" object, so that's better than just typing in error-prone literal strings.
tags: javascript sample_code
links: digg this technorati
