Programming Forums > Application Development > C++

glopal · May 3rd, 2005, 7:19 PM

Hey all yal, Im pretty new to programming in C++ so be patient with me.

I get these errors:

--------------------Configuration: battle - Win32 Debug--------------------
Compiling...
battle.cpp
Linking...
battle.obj : error LNK2001: unresolved external symbol "int __cdecl battle(char,int,int)" (?battle@@YAHDHH@Z)
battle.obj : error LNK2001: unresolved external symbol "int __cdecl randomfoe(char,int,int)" (?randomfoe@@YAHDHH@Z)
Debug/battle.exe : fatal error LNK1120: 2 unresolved externals
Error executing link.exe.

battle.exe - 3 error(s), 0 warning(s)

With this code:

(Toggle Plain Text)

#include <iostream.h>
#include <windows.h>
#include <stdlib.h>
#include <time.h>


//Prototyping-------------
int battle(char,int,int);
int randomfoe(char,int,int);

//------------------------

int main()
{
	char foename[15] = "";
	int foelvl = 0; 
	int map = 1;

	battle(foename[15],foelvl,map);
	return 0;

}

//////////////////////////////////////////////////////////

int battle(char foename[],int foelvl,int map)
{
	randomfoe(foename[15],foelvl,map);
	cout << "You are fighting a LVL "<< foelvl <<" " <<foename <<endl;
	return 0;


}

int randomfoe(char foename[],int foelvl,int map)
{
	short randfoelvl = 0;

	short randfoename = 0; 

	srand(time(NULL));
	
	randfoename = rand() + 1 % (3 - 1 + 1); 
	randfoelvl = rand() + 1 % (100 -1 + 1);

	
//RANDOM ENEMY NAME-------------------------------
	if (map = 1) 
	{
		if (randfoename == 1)
			foename = "Killer Mole";
		if (randfoename == 2)
			foename = "Crazed Bat";
		if (randfoename == 3)
			foename = "Giant Worm";
	
	}


	
//RANDOM ENEMY LEVEL------------------------------
	
	if (map = 1) 
	{
		if (randfoelvl >=1 && randfoelvl <=30)
			foelvl = 1;
		if (randfoelvl >=31 && randfoelvl <=80)
			foelvl = 2;
		if (randfoelvl >=81 && randfoelvl <=100)
			foelvl = 3;

	}

	return foelvl;

}

WHY? I personally think it has to do with me calling the randomfoe function from the battle function. How do I fix it?

uman · May 3rd, 2005, 9:00 PM

change this:
battle(foename[15],foelvl,map);

to this:
battle(foename,foelvl,map);

and change this:
int battle(char,int,int);

to this:
int battle(char[], int, int);

then do the same for the other function.

glopal · May 3rd, 2005, 9:06 PM

Thx no more errors, but now I have a new problem.

When I call the randomfoe function from the battle function it doesnt seem to work. When I execute, I shows LVL 0, and nothing for the name. Help please!

uman · May 3rd, 2005, 9:33 PM

C++ passes variables by value. If you don't know what this means, and whatever reference you're using to learn C++ doesn't explain it, you need to throw it away and get a new one.

Berto · May 4th, 2005, 3:45 AM

or in other words when passing a variable by value the original value of the variable does not change so when you pass a 2 to the function the variable when it returns from the funcition will still be 2.

This is why you have a return value from a function like you have it returning a int. Therefore you have to assign a variable to catch this int that is being returned(well you dont have to but its a good idea if returning somehting meaningful)

so chenge it from

(Toggle Plain Text)

randomfoe(foename[15],foelvl,map);

to

(Toggle Plain Text)

foelvl = randomfoe(foename[15],foelvl,map);

jhope this helps a little

Ooble · May 4th, 2005, 11:09 AM

Change char foename[15] in the function parameter declarations to char *foename, and char to char * in the prototypes at the top. Then pass foename, not foename[15] to the functions.

May 3rd, 2005, 7:19 PM	#1
glopal Newbie Join Date: May 2005 Location: St. Andrews, Manitoba, Canada Posts: 9 Rep Power: 0	Function Calls and Errors! Hey all yal, Im pretty new to programming in C++ so be patient with me. I get these errors: --------------------Configuration: battle - Win32 Debug-------------------- Compiling... battle.cpp Linking... battle.obj : error LNK2001: unresolved external symbol "int __cdecl battle(char,int,int)" (?battle@@YAHDHH@Z) battle.obj : error LNK2001: unresolved external symbol "int __cdecl randomfoe(char,int,int)" (?randomfoe@@YAHDHH@Z) Debug/battle.exe : fatal error LNK1120: 2 unresolved externals Error executing link.exe. battle.exe - 3 error(s), 0 warning(s) With this code: (Toggle Plain Text) #include <iostream.h> #include <windows.h> #include <stdlib.h> #include <time.h> //Prototyping------------- int battle(char,int,int); int randomfoe(char,int,int); //------------------------ int main() { char foename[15] = ""; int foelvl = 0; int map = 1; battle(foename[15],foelvl,map); return 0; } ////////////////////////////////////////////////////////// int battle(char foename[],int foelvl,int map) { randomfoe(foename[15],foelvl,map); cout << "You are fighting a LVL "<< foelvl <<" " <<foename <<endl; return 0; } int randomfoe(char foename[],int foelvl,int map) { short randfoelvl = 0; short randfoename = 0; srand(time(NULL)); randfoename = rand() + 1 % (3 - 1 + 1); randfoelvl = rand() + 1 % (100 -1 + 1); //RANDOM ENEMY NAME------------------------------- if (map = 1) { if (randfoename == 1) foename = "Killer Mole"; if (randfoename == 2) foename = "Crazed Bat"; if (randfoename == 3) foename = "Giant Worm"; } //RANDOM ENEMY LEVEL------------------------------ if (map = 1) { if (randfoelvl >=1 && randfoelvl <=30) foelvl = 1; if (randfoelvl >=31 && randfoelvl <=80) foelvl = 2; if (randfoelvl >=81 && randfoelvl <=100) foelvl = 3; } return foelvl; } #include <iostream.h> #include <windows.h> #include <stdlib.h> #include <time.h> //Prototyping------------- int battle(char,int,int); int randomfoe(char,int,int); //------------------------ int main() { char foename[15] = ""; int foelvl = 0; int map = 1; battle(foename[15],foelvl,map); return 0; } ////////////////////////////////////////////////////////// int battle(char foename[],int foelvl,int map) { randomfoe(foename[15],foelvl,map); cout << "You are fighting a LVL "<< foelvl <<" " <<foename <<endl; return 0; } int randomfoe(char foename[],int foelvl,int map) { short randfoelvl = 0; short randfoename = 0; srand(time(NULL)); randfoename = rand() + 1 % (3 - 1 + 1); randfoelvl = rand() + 1 % (100 -1 + 1); //RANDOM ENEMY NAME------------------------------- if (map = 1) { if (randfoename == 1) foename = "Killer Mole"; if (randfoename == 2) foename = "Crazed Bat"; if (randfoename == 3) foename = "Giant Worm"; } //RANDOM ENEMY LEVEL------------------------------ if (map = 1) { if (randfoelvl >=1 && randfoelvl <=30) foelvl = 1; if (randfoelvl >=31 && randfoelvl <=80) foelvl = 2; if (randfoelvl >=81 && randfoelvl <=100) foelvl = 3; } return foelvl; } WHY? I personally think it has to do with me calling the randomfoe function from the battle function. How do I fix it? Last edited by glopal; May 3rd, 2005 at 8:23 PM.

May 4th, 2005, 3:45 AM	#5
Berto Programming Guru Join Date: Aug 2004 Posts: 1,022 Rep Power: 6	or in other words when passing a variable by value the original value of the variable does not change so when you pass a 2 to the function the variable when it returns from the funcition will still be 2. This is why you have a return value from a function like you have it returning a int. Therefore you have to assign a variable to catch this int that is being returned(well you dont have to but its a good idea if returning somehting meaningful) so chenge it from (Toggle Plain Text) randomfoe(foename[15],foelvl,map); randomfoe(foename[15],foelvl,map); to (Toggle Plain Text) foelvl = randomfoe(foename[15],foelvl,map); foelvl = randomfoe(foename[15],foelvl,map); jhope this helps a little

May 4th, 2005, 11:09 AM	#6
Ooble I eat cake for breakfast. Join Date: Jul 2004 Location: In my box. Posts: 4,434 Rep Power: 9	Change char foename[15] in the function parameter declarations to *char foename, and char** to char * in the prototypes at the top. Then pass foename, not foename[15] to the functions. __________________ Me :: You :: Them Last edited by Ooble; May 4th, 2005 at 11:12 AM.

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May 3rd, 2005, 9:00 PM	#2
uman Expert Programmer Join Date: Dec 2004 Posts: 794 Rep Power: 4	change this: battle(foename[15],foelvl,map); to this: battle(foename,foelvl,map); and change this: int battle(char,int,int); to this: int battle(char[], int, int); then do the same for the other function.

May 3rd, 2005, 9:06 PM	#3
glopal Newbie Join Date: May 2005 Location: St. Andrews, Manitoba, Canada Posts: 9 Rep Power: 0	Thx no more errors, but now I have a new problem. When I call the randomfoe function from the battle function it doesnt seem to work. When I execute, I shows LVL 0, and nothing for the name. Help please!

May 3rd, 2005, 9:33 PM	#4
uman Expert Programmer Join Date: Dec 2004 Posts: 794 Rep Power: 4	C++ passes variables by value. If you don't know what this means, and whatever reference you're using to learn C++ doesn't explain it, you need to throw it away and get a new one.

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Programming Forums > Application Development > C++

Function Calls and Errors!