vector<int> a; // empty vector of integers
vector<int> b(10); // 10 integers, all 0
vector<int> c(5, -1); // 5 integers, all -1
vector<int> d(c); // d will be a copy of c
vector<string> p; // empty vector of strings
vector<string> q(5, "xyz"); // 5 strings, all "xyz"
vector<string> r(q); // r will be a copy of q
- Vectors are made available via
#include <vector>
- The type of value to be stored is specified inside
<>; this can even be another vector!
- Vectors can be declared empty or with an initial size and can grow or shrink after creation; declaring the initial size is more efficient than growing a vector from empty and should be done if you have a good idea of what your eventual storage requirements will be
- Elements are initialized to a default value, unlike arrays (see later); a specific initial value can also be provided at creation time
