If you're planning to use different variables types (like your AS snippet suggests), I'd recommend using one of (specialized) collections types.
If you only need a fixed list of strings or integers, an array would be a lighter solution.
Variable variables in C#
You could define a new native types layer utilizing the map feature so that it works identical to actionscript.
For example you could declare a intX or floatX type and invoke GetVarX( "var_name") or however you define it. You'd of course need to make sure to overload all the arithmetic operators so that they don't lose any flexibility over the real native types.
For example you could declare a intX or floatX type and invoke GetVarX( "var_name") or however you define it. You'd of course need to make sure to overload all the arithmetic operators so that they don't lose any flexibility over the real native types.
I think he's trying to get at variables that are just in a specific scope, not elements of some sort of dictionary or map. If that's the case, then he needs to use reflection. I posted code on how to do what he wants to do which will work to get at fields and properties of an object. I don't know how to just get at a variable that isn't part of an object:
using System.Reflection;using System;class dummy{ public int field; public int Property { get { return 10; }; }}void f(){ int someInt = 10; dummy c = new dummy(); Type dummyType = c.GetType(); int fieldValue = dummyType.GetField("fi" + "eld").GetValue(c); int propertyValue = propertyType.GetProperty("Prop" + "erty").GetValue(c); // now how do I get the value of "someInt" by name? It's not a // property or field, so I can't do a "GetType" on anything. Console.WriteLine("Value of field: {0}", fieldValue); Console.WriteLine("Value of Property: {0}", propertyValue);}
Quote:Original post by smr
I think he's trying to get at variables that are just in a specific scope, not elements of some sort of dictionary or map. If that's the case, then he needs to use reflection. I posted code on how to do what he wants to do which will work to get at fields and properties of an object. I don't know how to just get at a variable that isn't part of an object:
The simple answer is: You don't. You could, of course, build a preprocessor that would build an internal registry of variables that were added and removed from said registry as they came into scope and left scope, however such a process would be rather...stupid.
He could also build a varadic type with a centralized registry that on construction registered the variable and then he could fetch it from that registry (which is essencially what you would do with a dictionary), which is all _root really is (albeight with a bit more stuff in it).
Quote:Original post by Washu
He could also build a varadic type with a centralized registry that on construction registered the variable and then he could fetch it from that registry (which is essencially what you would do with a dictionary), which is all _root really is (albeight with a bit more stuff in it).
But wouldn't GetField and GetProperty accomplish the same thing? Since you have an actual object with a type, you can get at its fields with the GetX methods. Is there a concept in .NET like pythons "__locals__"?
Quote:Original post by _Danneman_
Does anything like that exist in C#?
Not exactly. But there are four ways to approximate this:
1.) Use the System.Reflection methods. For instance, to get the value of a field in a class, use the following.
using System;using System.Reflection;using System.Security;public class Dummy{ public string s = "stored string value"; public string X { get { return this.s; } set { this.s = value; } }}// Elsewhere in codepublic static void Main(){ // Use a try-catch block in real software to catch // SecurityExceptions that might arise. Dummy d1 = new Dummy(); Dummy d2 = new Dummy(); d2.X = "foo"; Type t = Type.GetType("Dummy"); FieldInfo fi = t.GetField("s"); // <-- equivalent variadic specification // prints "stored string value" Console.WriteLine("The value of the d1 field is: {0}", fi.GetValue(d1)); // prints "foo" Console.WriteLine("The value of the d2 field is: {0}", fi.GetValue(d2));}2.) Use a GenericDictionary to store name-value pairs.
3.) Use an array, if the values are all the same type.
4.) Wait for C# 3.0. Then you can use (3) even if the values aren't all the same type, and the compiler will infer their type from the way in which the value is used.
Quote:Original post by smr
But wouldn't GetField and GetProperty accomplish the same thing? Since you have an actual object with a type, you can get at its fields with the GetX methods. Is there a concept in .NET like pythons "__locals__"?
No, because the instances wouldn't need to be class members. That particular solution is ugly though.
string name = "v";int index = 1;...Var v1(name + index);v = something;...Var var = Var.Get(name + index);Disguised globals...silly idea.
This topic is closed to new replies.
Advertisement
Popular Topics
Advertisement
