标签：
size :返回有效元素个数
max_size :返回 vector 支持的最大元素个数
resize :改变有效元素的个数
capacity :返回当前可使用的最大元素内存块数（即存储容量）
empty :判断是否为空
reserve :请求改变存储容量
shrik_to_fit :请求移除未使用的存储空间
std::vector<int> foo; for (int i = 0; i<100; i++) foo.push_back(i); std::cout << "size: " << (int)foo.size() << ‘\n‘; std::cout << "capacity: " << (int)foo.capacity() << ‘\n‘; std::cout << "max_size: " << (int)foo.max_size() << ‘\n‘; foo.resize(5); foo.resize(8, 100); foo.resize(12); for (int i = 0; i < foo.size(); i++) std::cout << ‘ ‘ << foo[i]; std::cout << std::endl; int sum(0); while (!foo.empty()) { sum += foo.back(); foo.pop_back(); } std::cout << "total: " << sum << ‘\n‘; foo.reserve(200); //设置最小容量，返回值大于等于这个值 std::cout << "capacity: " << (int)foo.capacity() << ‘\n‘; //200,如果设置100，这里是141 foo.resize(5); foo.shrink_to_fit(); //请求移除不使用的空间 std::cout << "capacity: " << (int)foo.capacity() << ‘\n‘; //5
[] at
front 访问第一个元素
back 访问最后一个元素
data 返回当前向量内部数组的指针
#include <iostream> #include <vector> int main() { std::vector<int> foo(5); int* p = foo.data(); *p = 10; ++p; *p = 20; p[2] = 100; std::cout << "foo.front() is now " << foo.front() << std::endl; std::cout << "foo:"; for (unsigned i = 0; i<foo.size(); ++i) std::cout << ‘ ‘ << foo[i]; std::cout << std::endl; return 0; }
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原文地址：http://www.cnblogs.com/yuguangyuan/p/5845030.html
