hard C++ question!

[Nessoldaccount]

Let's say you have a string containing "anandtech"

you have a variable named "anandtech"

how can I take the string and match it up with the variable of the same name to perform a function?

 

[jmcoreymv]

you could do a switch statement, but there might be an easier way.

 

[Nessoldaccount]

a switch statement would be way too much work because there are too many possibilities.

 

[jmcoreymv]

Hmm if you figure it out, post it here, id like to know.

 

[Descartes]

This doesn't quite make sense to me... you have a string "anandtech" and you want to match it up against another string "anandtech", and if it proves equal, you want to call a function?

Well, unless I'm way off base (in which case you'll need to clarify yourself), this would be a general solution:

char *s = "anandtech";
if (!strcmp(s, "anandtech&quot)
doSomething();

 

[Nessoldaccount]

no it's like this.

string name = "anandtech"
variable anandtech

if(contents of name == name of variable)
doSomething();

 

[jmcoreymv]

Pretender I think he wants to have the user input a string, and basicly it takes that input as the name of the function and runs it. Supposedly there are too many functions to use a switch or if statement.

 

[MickySoft]

Well, do you know the variable name that you want to use? If you do, then you could just use a simple strcmp function. If not, then I believe it's very hard(if it's possible) to know the name of the variable during execution time.

 

[prodigy]

<< Pretender I think he wants to have the user input a string..... >>



Heh, did you think that was Pretender responding because of the &quot;snowman&quot; icon?

 

[hans007]

that seems very close to impossible. Why would you want a user to reference a specific variable name anyways, you cant have infinte variables and the user could inputanything. The inner code is supposed to be transparent to the user, maybe you make an object with a name in its private member, but i dont understand why you'd do it with just a plain variable.

 

Just use a hashtable to key the variable off of the string.

There is no way at runtime for the language to know the name of the variable, so this is going to be the cleanest way to do it.

int foo = 100;
int bar = 200;
...
map m = map<char* int>;
m.add(&quot;foo&quot;, foo);
m.add(&quot;bar&quot;, bar);
...
void doSomeThing(char* key)
{
____if(m.hasKey(key))
_______int i = (int)m.get(key);
...
}

 

[HigherGround]

or you can use the # preprocessor operator...lets say we define VARSTRCMP to return 1 if the contents of str match the name of var.


#define VARSTRCMP(var, str) !strcmp(&quot;&quot;#var&quot;&quot;, (const char*)str);

int main(int argc, void **argv)
{
int anandtechVar = 5;
const char anandtechStr[] = &quot;anandtechVar&quot;;

int compare = VARSTRCMP(anandtechVar, anandtechStr);

// compare is equal to 1 if the anandtechStr holds the value equal to the name of the first parameter - in this case anandtechStr. Otherwise it's 0 or 1.

return 0;
}


i think thats what you want.