I want a function to be able to take in various types. AS3 doesn't support overloading directly... so I can't do the following:
//THIS ISN'T SUPPORTED BY AS3
function someFunction(xx:int, yy:int, someBoolean:Boolean = true){
//blah blah blah
}
function someFunction(arr:Array, someBoolean:Boolean = true){
someFunction(arr[0], arr[1], someBoolean);
}
How can I work around it and still have a function that is able to take arguments of various types?
You overload a function name f by declaring more than one function with the name f in the same scope. The declarations of f must differ from each other by the types and/or the number of arguments in the argument list.
Unlike the other programming languages, JavaScript Does not support Function Overloading.
Function overloading is a feature of object-oriented programming where two or more functions can have the same name but different parameters. When a function name is overloaded with different jobs it is called Function Overloading.
TypeScript provides the concept of function overloading. You can have multiple functions with the same name but different parameter types and return type. However, the number of parameters should be the same.
If you just want to be able to accept any type, you can use *
to allow any type:
function someFunction( xx:*, yy:*, flag:Boolean = true )
{
if (xx is Number) {
...do stuff...
} else if (xx is String) {
...do stuff...
} else {
...do stuff...
}
}
If you have a large number of various parameters where order is unimportant, use an options object:
function someFunction( options:Object )
{
if (options.foo) doFoo();
if (options.bar) doBar();
baz = options.baz || 15;
...etc...
}
If you have a variable number of parameters, you can use the ...
(rest) parameter:
function someFunction( ... args)
{
switch (args.length)
{
case 2:
arr = args[0];
someBool = args[1];
xx = arr[0];
yy = arr[1];
break;
case 3:
xx = args[0];
yy = args[1];
someBool = args[2];
break;
default:
throw ...whatever...
}
...do more stuff...
}
For cases where you need to call a common function to a number of classes, you should specify the interface common to each class:
function foo( bar:IBazable, flag:Boolean )
{
...do stuff...
baz = bar.baz()
...do more stuff...
}
Could just have:
function something(...args):void
{
trace(args[0], args[1]);
}
This way you can easily loop through your arguments and such too (and even check the argument type):
function something(...args):void
{
for each(var i:Object in args)
{
trace(typeof(i) + ": " + i);
}
}
something("hello", 4, new Sprite()); // string: hello
// number: 4
// object: [object Sprite]
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