C++ Vector size()

It determines the number of elements in the vector.

Syntax

Consider a vector 'v' and number of elements 'n'. Syntax would be :

Parameter

It does not contain any parameter.

Return value

It returns the number of elements in the vector.

Example 1

Let's see a simple example.

#include<iostream>
#include<vector>
using namespace std;
int main()
{
	vector<string> v{"Welcome to javaTpoint","c"};
	int n=v.size();
	cout<<"Size of the string is :"<<n;
	return 0;
}

Output:

Size of the string is:2

In this example, vector v containing two strings and size() function gives the number of elements in the vector.

Example 2

Let's see a another simple example.

#include<iostream>
#include<vector>
using namespace std;
int main()
{
	vector<int> v{1,2,3,4,5};
	int n=v.size();
	cout<<"Size of the vector is :"<<n;
	return 0;
}

Output: