Would it be possible to initialize a vector array of strings?
for example:
static std::vector<std::string> v; //declared as a class member
I used static just to initialize and fill it with strings. Or should i just fill it in the constructor if it can't be initialized like we do with regular arrays.
It is 2017, but this thread is top in my search engine, today the following methods are preferred (initializer lists)
std::vector<std::string> v = { "xyzzy", "plugh", "abracadabra" };
std::vector<std::string> v({ "xyzzy", "plugh", "abracadabra" });
std::vector<std::string> v{ "xyzzy", "plugh", "abracadabra" };
From https://en.wikipedia.org/wiki/C%2B%2B11#Initializer_lists
Sort of:
class some_class {
static std::vector<std::string> v; // declaration
};
const char *vinit[] = {"one", "two", "three"};
std::vector<std::string> some_class::v(vinit, end(vinit)); // definition
end is just so I don't have to write vinit+3 and keep it up to date if the length changes later. Define it as:
template<typename T, size_t N>
T * end(T (&ra)[N]) {
return ra + N;
}
sizeof(char*) is 4, yes. Not so much on a 64bit machine. I just got bored of typing a bunch of sizeof stuff every time I iterate an array. My end function has the same effect for arrays as std::end in C++0x does.end function, I mean the function template in my answer, in contrast with C++0x's std::end. I don't claim to have invented it!
N is deduced as 3 from the type of the argument vinit, which is const char* [3]. For that matter, T is also deduced as const char * from that same type. So writing end(vinit) is like writing end<const char*, 3>(vinit) thanks to template parameter deduction.If you are using cpp11 (enable with the -std=c++0x flag if needed), then you can simply initialize the vector like this:
// static std::vector<std::string> v;
v = {"haha", "hehe"};
const char* args[] = {"01", "02", "03", "04"};
std::vector<std::string> v(args, args + 4);
And in C++0x, you can take advantage of std::initializer_list<>:
MSVC 2010 solution, since it doesn't support std::initializer_list<> for vectors but it does support std::end
const char *args[] = {"hello", "world!"};
std::vector<std::string> v(args, std::end(args));
same as @Moo-Juice:
const char* args[] = {"01", "02", "03", "04"};
std::vector<std::string> v(args, args + sizeof(args)/sizeof(args[0])); //get array size
Take a look at boost::assign.
In C++0x you will be able to initialize containers just like arrays
Main thing is static will not help in initializing and filling the vector with strings.
But can be initialized like mentioned below when it is declared. (There are some more examples in other answers)
//JUST AN EMPTY VECTOR, BUT THAT CAN HOLD std::string type.
std::vector<std::string> vecStr;
//AN INITIALIZED VECTOR OF TWO EMPTY STRINGS.
std::vector<std::string> vecString(2);
//AN INITIALIZED VECTOR OF TWO STRINGS WITH "testing"
std::vector<std::string> anotherVecString(2, "testing");
staticdoesn't "fill it with strings". The std::vector is a dynamic data structure and is created empty.staticin this context means multiple instances of your class all share the samev, is that what you really want?