C++ Vector begin
This function is used to point the first element of the vector.
begin vs front
The begin function is used to return an iterator pointing to the first element of the vector while front function is used to return a reference to the same element in the vector container.
Syntax
Consider a vector 'v' and syntax would be:
Example
iterator it =v.begin();
Parameter
It does not contain any parameter.
Return value
It returns an iterator pointing to the first element of the vector.
Example 1
Let's see a simple example.
Example
#include <iostream>
#include<vector>
using namespace std;
int main()
{
vector<char> v{'a','e','i','o','u'};
vector<char>::iterator itr;
itr=v.begin();
cout<<*itr;
return 0;
}
Output:
In this example, object of iterator 'itr' is created to access begin function and 'itr' is of vector type containing character values.
Example 2
Let's see a another simple example.
Example
#include <iostream>
#include<vector>
using namespace std;
int main()
{
vector<int> v{1,2,3,4,5};
vector<int>::iterator itr;
itr=v.begin()+2;
cout<<*itr;
return 0;
}
Output:
In this example, begin function is incremented by 2 to access the third element of the vector.