需要帮助打印字符串

Question

Im currently learning about classes in C++. Im coming from a java language background.

I have a class called animals. the animals constructor has a parameter in which a string is required. When i create an object of that class and try to print out the string that was passed to the constructor, it doesn't print out anything apart from a new line..

ANIMAL CLASS

    #include "animal.h"
#include <string>
#include <iostream>
using namespace std;


animal::animal(string nameofanimal)
{

    string name = nameofanimal;
}

void animal::getName(){
    cout << name << endl;
}

ANIMAL HEADER:

#pragma once
#ifndef ANIMAL_H
#define ANIMAL_H
#include <string>
#include <iostream>
using namespace std;


class animal
{

private:
    string name;

public:
    animal(string x);
    void getName();


};

#endif ANIMAL_H

MAIN CLASS

#include "animal.h"
#include <string>
#include <iostream>
using namespace std;



int main()
{
    animal firstAnimal("Bob");
    firstAnimal.getName();

}

the output is nothing. this is a very basic code and honestly cant believe I don't know how to do such a simple task. What I have noticed is that whenever I highlight the name varible in the animals constructor, the varible name in the getName() function doesn't highlight so im guessing this has something to do with pointers... I may be wrong though...

Answer 1

Change your animal constructor definition as follows

animal::animal(string nameofanimal) : name(nameofanimal) {
}

In your original definiton you have a local variable name that shadows the class member variable:

animal::animal(string nameofanimal)
{    
    string name = nameofanimal; // <<< This sets only the local variable
}

Answer 2

The problem is you are storing value in local variable

string name = nameofanimal;

while the value is not stored in actual data member of the class. To store it in data member use the following:

name = nameofanimal;