C++ Passing Variables Between Classes

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SUMMARY

This discussion focuses on the challenges of passing variables between classes in C++. The user attempts to pass variables var1 and var2 from Class1 to Class2 but encounters garbage values when attempting to display them. Key insights include the necessity of using commas to separate parameters in function calls and the importance of initializing pointers to avoid undefined behavior. A recommendation is made to create a minimal, complete example program to isolate and identify the issue effectively.

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  • Understanding of C++ class structure and syntax
  • Familiarity with function parameter passing in C++
  • Knowledge of pointer initialization and memory management
  • Basic debugging techniques in C++
NEXT STEPS
  • Learn about C++ function parameter types and how to define them correctly
  • Explore C++ debugging techniques to identify and resolve garbage value issues
  • Study how to create minimal reproducible examples in C++ for troubleshooting
  • Investigate best practices for pointer initialization and memory management in C++
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Beginner C++ programmers, software developers working with class structures, and anyone looking to improve their debugging skills in C++.

chronie
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Hi,

I am new to programming, but I think this is a simple error. For my programming code I am trying to pass a variable from a certain class to another class. The code is similar to below.Class 1
PHP:
#include "class2"

Class2 class

var1=1
var2=2

class.acceptingvariablesfrom1(var1 var2)

Class 2
PHP:
class.acceptingvariablesfrom1(var1 var2)

count << var1 << endl;

That is what my basic code looks like. I send my var1 and var2 to my acceptingvariablesclass however, how do I have them displayed. When I do my count statement I get garbage. Am I doing something wrong? Class1 and Class2 are different .cpp files. In Class2 do I have to define var1 and var2 again even though they were defined in class1?

I think this is a basic question but I just don't understand why I am getting garbage values?
 
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You need to use commas to separate the variables.
 
I'm sorry, in my real code I had commas. I am just confused as to why garbage values print out.
 
Post the actual code with declarations. This sample is nothing. (what are var1 and var2? ) And what param types is the function expecting?

Garbage could be from anywhere in your code if you trashed a pointer somewhere.

Create a small simple program that tests the classes, that will at least isolate whether it is the class or not.
 
Agreed. The best thing to do is construct a short, complete example program that can be pasted into a compiler and compiled successfully, and that demonstrates the problem.
 
Besides, with this approach 9 times out of 10 you will find the problem by yourself.
 
Borek said:
Besides, with this approach 9 times out of 10 you will find the problem by yourself.

Yep. My daughter is a Comp Eng and she took a Comp Sci programming course, which was C at her University. I was shocked at how the prof. didn't teach the students proper style or technique. She stopped showing me her projects because I would get on her.

Not initializing pointers? That is not a style preference, it is a must do.

I think that is where the experience really comes into play; debugging.
 

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