Variable variables

[sassur]

In PHP you can do this

 

$name = "Fredrik";

$var = "name";

echo ${$var};

 

and the output will be

 

Fredrik

 

Now I wonder if you can do somethins similar in C# or VB.NET?

 

---

Sassur

[Bodybag]

dim s as string= "John"

 

response.write (s)

[sassur]

dim s as string= "John"

 

response.write (s)

 

For a starter thats classic VB I asked about C# or VB.NET.

 

And thats not what I asked for.

 

I know how to define a variable and print it to the page.

[bungpeng]

In VBScript, we can use "ESCAPE" and "EXECUTE", but I not sure whether VB.NET can use it.

[samsmithnz]

Its almost exactly the same in C#.

 

string s = "John";

response.write (s); 

[sassur]

Its almost exactly the same in C#.

 

string s = "John";

response.write (s); 

 

But as I said i the previous post, that isn't what I'm asking for.

 

Trying to explain better:

$name1 = "Fredrik";
$name2 = "Andreas";

$var = "name1";
echo $var . " = " . ${$var};
echo "<br>";

$var = "name2";
echo $var . " = " . ${$var};
echo "<br>";

 

and the output will be

 

 
name1 = Fredrik
name2 = Andreas

[Bodybag]

dim s1 as string = "jack"

dim s2 as string = "Daniels"

 

label1.text = "i drink " & s1 & " " & s2 & "<br>"

[samsmithnz]

Am I the only one that doesn't understand what you're asking for exactly?

[Bodybag]

I am a little lost myself.

[sassur]

It look's more complicated then it is. The key to it is the variable $var

 

I will try to explane each line by it self

 

$name1 = "Fredrik";

initiates $name1 to Fredrik

 

$name2 = "Andreas";

initiates $name2 to Andreas

 

$var = "name1";

initiates $var to name1

 

echo $var . " = " . ${$var};

this will print :

name1 = Fredrik

 

take a look at ${$var}, that code means:

the variable with the name in variable $var

therefore

${$var} equels the variable $name1

 

echo "<br>";

prints "<br>"

 

$var = "name2";

set $var to name2

 

echo $var . " = " . ${$var};

name1 = Andreas

now the variable $var conatins name2

therefore

${$var} equels the variable $name2

 

echo "<br>";

prints "<br>"

 

Hoppes this makes it a little clearer.

[PlausiblyDamp]

Not sure if you can do it exactly the way you say but you could achieve something similar with a collection.

 

	Dim vars As New Collections.Specialized.StringDictionary

	vars.Add("Name1", "Frederik")
	vars.Add("Name2", "Andreas")

	Dim name As String = "Name1"
	Response.writeline(vars(name)

[sassur]

Not sure if you can do it exactly the way you say but you could achieve something similar with a collection.

 

	Dim vars As New Collections.Specialized.StringDictionary

	vars.Add("Name1", "Frederik")
	vars.Add("Name2", "Andreas")

	Dim name As String = "Name1"
	Response.writeline(vars(name)

 

Thanks, but not exactly that.

 

It seams that you cant use the Eval function to achieve what I want, but i havenät looked into it very deeply.

[samsmithnz]

Why do you need to print the variable names?

[PlausiblyDamp]

Could you give us a reason why you need to do it that way? There may be a better alternative in ASP.Net.

[iebidan]

I don't see the use for what you're asking, seems to me like more memory consumption, if I want to copy the value of 1 variable into another variable I'll do something really simple

string name1 = "Superman";
string name2 = "Batman";

name1 = name2;

There you go, I assigned the value of the second variable into the first one, what's the result ? "BATMAN", why do things the hard way?????, this is exactly the same thing you're doing

[samsmithnz]

I don't see the use for what you're asking, seems to me like more memory consumption, if I want to copy the value of 1 variable into another variable I'll do something really simple

string name1 = "Superman";
string name2 = "Batman";

name1 = name2;

There you go, I assigned the value of the second variable into the first one, what's the result ? "BATMAN", why do things the hard way?????, this is exactly the same thing you're doing

 

I think he's trying to print the actual name of the variable too. Thats the main difference.

[vbFace]

Sounds like the orig. example is a pseudo-pointer in php. No pointers in VB.NET I believe.