public member function

vector::empty

bool empty () const;
Test whether vector is empty
Returns whether the vector container is empty, i.e. whether its size is 0.

This function does not modify the content of the vector in any way. To clear the content of a vector, use vector::clear.

Parameters

none

Return Value

true if the vector size is 0, false otherwise.

Example

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// vector::empty
#include <iostream>
#include <vector>
using namespace std;

int main ()
{
  vector<int> myvector;
  int sum (0);

  for (int i=1;i<=10;i++) myvector.push_back(i);

  while (!myvector.empty())
  {
     sum += myvector.back();
     myvector.pop_back();
  }

  cout << "total: " << sum << endl;
  
  return 0;
}

The example initializes the content of the vector to a sequence of numbers (form 1 to 10). It then pops the elements one by one until it is empty and calculates their sum.

Output:
total: 55

Complexity

Constant.

See also

vector::clear
Clear content (public member function)
vector::erase
Erase elements (public member function )
vector::size
Return size (public member function)