Thread: Where am I going wrong?

But a lot of those books are not in C++ 20!

Originally Posted by Salem

C++ Book Recommendations

Originally Posted by Salem

So?

You're struggling with fundamentals.

Get a solid few months experience of basic C++ before you start worrying about the latest toys in C11/14/17/20/23.

But I have been doing cpp for two years! And all studies show all takes to become good at something takes 30 hours of time spent on it.

Plus, I am confused with the order and why it isn't working when I believe I read it right...a simple problem I can do. Something more advanced? Probably struggle...

Originally Posted by Salem

30 hours of C++ is enough to tell the difference between a C++ program and a hole in the ground.

30 hours should be long enough to learn how to write a basic class. But maybe OP has only one hour to spend on C++ each month? So they're only about 24 hours in to the 30 that are required to learn how to write a class.

Originally Posted by Salem

Given a problem statement like this:
"Create a class called Dog with attributes age, weight and color. Add suitable set/get methods".
You should be able to produce that class without resorting to looking at pretty cartoon pictures.

Bae please!

Does code go something like this:

Code:

#include<iostream>
#include<string>
using namespace std;

class Dog{

       int age;
       int weight;
       string color;

        Yeah, the other stuff seems hard.

Originally Posted by christop

30 hours should be long enough to learn how to write a basic class. But maybe OP has only one hour to spend on C++ each month? So they're only about 24 hours in to the 30 that are required to learn how to write a class.

Where did I go wrong with the first example? Member variables are age, etc, member functions are what?

Originally Posted by solidusMGS

Where did I go wrong with the first example? Member variables are age, etc, member functions are what?

Your first example (in post #1) didn't have member variables, and the member functions tried to access those non-existent member variables. This was pointed out in post #3.

Originally Posted by christop

Your first example (in post #1) didn't have member variables, and the member functions tried to access those non-existent member variables. This was pointed out in post #3.

But I followed the book letter-by-letter!

Originally Posted by solidusMGS

But I followed the book letter-by-letter!

But which step says to remove the member variables? Note that you were already asked about that in post #13.

Here's what I get when I follow the steps letter-by-letter (I didn't implement main since some of the steps were cut off). This code compiles without warnings (even with the -Wall -Wextra -Wpedantic compiler flags):

Code:

// step 1
#include <string>
#include <iostream>
using namespace std;

// step 2
class Dog
{
// step 3
private:
        int age, weight;
        string color;
// step 4
public:
// step 5
        void bark() { cout << "WOOF!" <<endl; }

// step 6
        // void setAge(int yrs) { age = yrs; }
        // void setWeight(int lbs) { weight = lbs; }
        // void setColor(string hue) { color = hue; }
// multiple step 2 (replace the three setter methods (above) with a single combined setter prototype)
        void setValues(int, int, string);

// step 7
        int getAge() { return age; }
        int getWeight() { return weight; }
        string getColor() { return color; }
};

// multiple step 3
void Dog::setValues(int age, int weight, string color)
{
// multiple step 4
        this->age = age;
        this->weight = weight;
        this->color = color;
}

That's what I thought, but I read in the text, it said to leave the setters original and to just add the new setters. Maybe I'm just crazy and stupid.

See you down at Arizona Bay!

Originally Posted by christop

But which step says to remove the member variables? Note that you were already asked about that in post #13.

Here's what I get when I follow the steps letter-by-letter (I didn't implement main since some of the steps were cut off). This code compiles without warnings (even with the -Wall -Wextra -Wpedantic compiler flags):

Code:

// step 1
#include <string>
#include <iostream>
using namespace std;

// step 2
class Dog
{
// step 3
private:
        int age, weight;
        string color;
// step 4
public:
// step 5
        void bark() { cout << "WOOF!" <<endl; }

// step 6
        // void setAge(int yrs) { age = yrs; }
        // void setWeight(int lbs) { weight = lbs; }
        // void setColor(string hue) { color = hue; }
// multiple step 2 (replace the three setter methods (above) with a single combined setter prototype)
        void setValues(int, int, string);

// step 7
        int getAge() { return age; }
        int getWeight() { return weight; }
        string getColor() { return color; }
};

// multiple step 3
void Dog::setValues(int age, int weight, string color)
{
// multiple step 4
        this->age = age;
        this->weight = weight;
        this->color = color;
}