std::vector::size

size_type size() const;

Returns the number of elements in the container, i.e. std::distance(begin(), end()).

Parameters

(none).

Return value

The number of elements in the container.

Exceptions

(none)	(until C++11)
`noexcept` specification: `noexcept`	(since C++11)

Complexity

Constant.

Example

The following code uses size to display the number of elements in a std::vector<int>:

#include <vector>
#include <iostream>
 
int main()
{ 
    std::vector<int> nums {1, 3, 5, 7};
 
    std::cout << "nums contains " << nums.size() << " elements.\n";
}

Output:

nums contains 4 elements.

capacity	returns the number of elements that can be held in currently allocated storage (public member function)
empty	checks whether the container is empty (public member function)
max_size	returns the maximum possible number of elements (public member function)
resize	changes the number of elements stored (public member function)

Links:

http://en.cppreference.com/w/cpp/container/vector/size

doc_CPP

2016-10-11 10:08:20

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