nazerke
11/28/2019 - 2:37 PM

## vectors

• vector is like C array
``````// vector.cpp by Bill Weinman <http://bw.org/>
// updated 2018-10-31
#include <iostream>
#include <string>
#include <vector>
using namespace std;

int main() {
cout << "Vector from initializer list: " << endl;
vector<int> vi1 = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

cout << "size: " << vi1.size() << endl;
cout << "front: " << vi1.front() << endl;
cout << "back: " << vi1.back() << endl;

// iterator
cout << endl << "Iterator:" << endl;
vector<int>::iterator itbegin = vi1.begin();
vector<int>::iterator itend = vi1.end();
for (auto it = itbegin; it < itend; ++it) {
cout << *it << ' ';
}
cout << endl;

cout << endl << "Index:" << endl;
cout << "element at 5: " << vi1[5] << endl;
cout << "element at 5: " << vi1.at(5) << endl;

cout << endl << "Range-based for loop:" << endl;
for (int & i : vi1) {
cout << i << ' ';
}
cout << endl;

cout << endl << "Insert 42 at begin + 5: " << endl;
vi1.insert(vi1.begin() + 5, 42);
cout << "size: " << vi1.size() << endl;
cout << "vi1[5]: " << vi1[5] << endl;

cout << "Erase at begin + 5: " << endl;
vi1.erase(vi1.begin() + 5);
cout << "size: " << vi1.size() << endl;
cout << "vi1[5]: " << vi1[5] << endl;

cout << "push_back 47: " << endl;
vi1.push_back(47);
cout << "size: " << vi1.size() << endl;
cout << "vi1.back() " << vi1.back() << endl;

cout << "Range-based for loop: " << endl;
for(int & v : vi1) {
cout << v << ' ';
}
cout << endl << endl;

// from C-array
const static size_t size = 10;
int ia[size] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
cout << endl << "Vector from C-array: " << endl;
vector<int> vi2(ia, ia + size);
for( int & i : vi2 ) {
cout << i << ' ';
}
cout << endl << endl;

// vector of strings
cout << "Vector of strings:" << endl;
vector<string> vs = { "one", "two", "three", "four", "five" };
for(string & v : vs) {
cout << v << endl;
}

return 0;
}
``````