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
