set begin() in C++

begin(): This function returns a read-only (constant) iterator that points to the 

first element in the set. 

Note: Iteration is done in ascending order according to the keys. 

This function is available in the below file.

File: stl_set.h

Parameters: No Parameters are required for this function.

Syntax:

set<data_type>::const_iterator it = st.begin()

For Example:

st ={1,2,3,4}

st.begin() = > It returns iterator to the first element (i.e 1)

Approach

C++

#include <bits/stdc++.h>
using namespace std;

int main()
{
    set<int> st;
    st.insert(4);
    st.insert(2);
    st.insert(3);
    st.insert(1);

    set<int>::const_iterator it = st.begin();

    cout << *it << "\n";

    return 0;
}