CPP Vector with Array

Simple Note

Code

#include <iostream> 
#include <vector>

using namespace std;

/** Test basic vector operation with array,
 *
 * From http://www.cplusplus.com/reference/vector/vector/
 *        Vectors are sequence containers representing arrays that can change in size.
 *
 *        Just like arrays, vectors use contiguous storage locations for their elements,
 *        which means that their elements can also be accessed using offsets on regular pointers
 *        to its elements, and just as efficiently as in arrays. But unlike arrays, their size
 *        can change dynamically, with their storage being handled automatically by the container.
 */
void testBasic ();
void testInitialWithArray ();
int main() {
    testBasic();
    testInitialWithArray();
    system("PAUSE");
    return 0;
}

void testBasic () {
    cout << "function testBasic" << endl;
    // declare and init with size and default value
    // first param for size
    // second param for default value
    vector<int> intVector(5, 3);
    // declare and init with another vector
    // the values will be copied from intVector to intVectorTwo
    // change the value of intVectorTwo will not affect intVector
    vector<int> intVectorTwo(intVector);
    // declare int vector
    vector<int> intVectorThree(5);
    intVectorTwo[3] = 5;
    // init
    // vector knows the size itself
    for (int i = 0; i < intVectorThree.size(); i++) {
        intVectorThree[i] = 3*i;
    }
    // output content of vector
    cout << "output initVector: ";
    for (int i = 0; i < intVector.size(); i++) {
        if (i > 0) {
            cout << ", ";
        }
        cout << intVector[i];
    }
    
    cout << endl << "output initVectorTwo: ";
    for (int i = 0; i < intVectorTwo.size(); i++) {
        if (i > 0) {
            cout << ", ";
        }
        cout << intVectorTwo[i];
    }
    cout << endl << "output initVectorThree: ";
    for (int i = 0; i < intVectorThree.size(); i++) {
        if (i > 0) {
            cout << ", ";
        }
        cout << intVectorThree[i];
    }
    cout << endl << endl;
}

void testInitialWithArray () {
    cout << "function testInitialWithArray" << endl;
    int arr[] = {1, 3, 5};
    // declare and init with array
    vector<int> intVector(arr, arr+3);
    // declare and init with partial array
    vector<int> intVectorTwo(arr+1, arr+3);
    // output content of vector
    cout << "output initVector: ";
    for (int i = 0; i < intVector.size(); i++) {
        if (i > 0) {
            cout << ", ";
        }
        cout << intVector[i];
    }
    cout << endl << "output initVectorTwo: ";
    for (int i = 0; i < intVectorTwo.size(); i++) {
        if (i > 0) {
            cout << ", ";
        }
        cout << intVectorTwo[i];
    }
    cout << endl << endl;
}

Result

References

Vector
http://www.cplusplus.com/reference/vector/vector/

Download

https://github.com/benbai123/C_Cplusplus_Practice/blob/master/CPP/CPP_Basic/Vector/vector_with_array.cpp