I have this code:
class myclass
{
std::string str;
public:
void setStr(std::string value)
{
str=value;
}
std::string getStr()
{
return str;
}
}
main()
{
myclass ms;
std::cout<<ms.getStr()<<std::endl;
}
when I compile and run this code, there is o error and in windows I am always getting str as "".
Is this always valid?
I need the above behavior in the fact that if user did not call set, str would be always a blank string.
should I initialize str in constructor as follow:
class myclass
{
std::string str;
public:
myclass():str(""){}
void setStr(std::string value)
{
str=value;
}
std::string getStr()
{
return str;
}
}
I want to make sure that behavior is the same on all platform and also make sure that code is as small and neat as possible.
The standard advice in c++ is always initialize all your variables. So yes, you should initialize it. That's just good practice.
std::string::clear in C++The string content is set to an empty string, erasing any previous content and thus leaving its size at 0 characters.
We'd like to initialise it. For example: class UserName { std::string mName; public: UserName(const std::string& str) : mName(str) { } }; As you can see a constructor is taking const std::string& str .
Because the declaration of class string is in the namespace std. Thus you either need to always access it via std::string (then you don't need to have using) or do it as you did. Save this answer.
Do I need to initialize std::string
No. std::string
default constructor initialises a nice empty string for you.
I want to make sure that behavior is the same on all platform and also make sure that code is as small and neat as possible.
Remove clutter then:
struct myclass {
std::string str;
};
Fundamental types though, do not get initialised by default, you need to initialize them explicitly:
struct myclass {
std::string str;
int i = 1; // <--- initialize to 1.
};
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