初始化字符串的向量数组

Question

是否可以初始化字符串的向量数组.

例如:

static std::vector<std::string> v; //声明为类成员

我static只是用来初始化并用字符串填充它.或者我应该在构造函数中填充它,如果它不像我们常规数组那样初始化.

Answer 1

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;
}

Answer 2

如果您正在使用cpp11(-std=c++0x如果需要,可以使用标志启用),那么您可以像这样简单地初始化向量:

// static std::vector<std::string> v;
v = {"haha", "hehe"};

Answer 3

这是2017年,但是这个帖子在我的搜索引擎中排名第一,今天首选以下方法(初始化列表)

std::vector<std::string> v = { "xyzzy", "plugh", "abracadabra" };
std::vector<std::string> v({ "xyzzy", "plugh", "abracadabra" });
std::vector<std::string> v{ "xyzzy", "plugh", "abracadabra" }; 

来自https://en.wikipedia.org/wiki/C%2B%2B11#Initializer_lists

Answer 4

 const char* args[] = {"01", "02", "03", "04"};
 std::vector<std::string> v(args, args + 4);

在C++ 0x中,您可以利用std::initializer_list<>:

http://en.wikipedia.org/wiki/C%2B%2B0x#Initializer_lists

Answer 5

MSVC 2010解决方案,因为它不支持std::initializer_list<>向量,但它确实支持std::end

const char *args[] = {"hello", "world!"};
std::vector<std::string> v(args, std::end(args));

Answer 6

和@ Moo-Juice一样:

const char* args[] = {"01", "02", "03", "04"};
std::vector<std::string> v(args, args + sizeof(args)/sizeof(args[0])); //get array size