Question

How to use pointer to vector in C++

Answer 1

#include <iostream>
#include <vector>
#include <string>

using std::cout;
using std::endl;
using std::vector;
using std::string;

void print(const vector<string> *const p) {
	for (vector<string>::const_iterator it = (*p).begin(); it != (*p).end(); it++)
		cout << *it << endl;
}

int main()
{
	vector<string> *v = new vector<string>(3);

	v->at(0) = "c++";
	v->at(1) = "php";
	v->at(2) = "java";

	print(v);

	delete v;

	return 0;
}


/*
run:

c++
php
java

*/

 

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Answer 2

#include <iostream>
#include <vector>
#include <string>

using std::cout;
using std::endl;
using std::vector;
using std::string;

int main()
{
	vector<string> *v = new vector<string>(3);

	v->at(0) = "c++";
	v->at(1) = "php";
	v->at(2) = "java";

	cout << v->operator[](0) << endl;
	cout << v->operator[](1) << endl;
	cout << v->operator[](2) << endl;

	delete v;

	return 0;
}


/*
run:

c++
php
java

*/

 

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Answer 3

#include <iostream>
#include <vector>
#include <string>

using std::cout;
using std::endl;
using std::vector;
using std::string;

int main()
{
	vector<string> *v = new vector<string>(3);

	v->at(0) = "c++";
	v->at(1) = "php";
	v->at(2) = "java";

	for (int i = 0; i < v->size(); i++)
		cout << v->operator[](i) << endl;

	delete v;

	return 0;
}


/*
run:

c++
php
java

*/

 

70+ SQL courses for beginners and professionals

Answer 4

#include <iostream>
#include <vector>
#include <string>

using std::cout;
using std::endl;
using std::vector;
using std::string;

int main()
{
	vector<string> *v = new vector<string>(3);

	(*v)[0] = "c++";
	(*v)[1] = "php";
	(*v)[2] = "java";

	for (int i = 0; i < v->size(); i++)
		cout << (*v)[i] << endl;

	delete v;

	return 0;
}


/*
run:

c++
php
java

*/

 

70+ SQL courses for beginners and professionals

Answer 5

#include <iostream>
#include <vector>
#include <string>

using std::cout;
using std::endl;
using std::vector;
using std::string;

int main()
{
	vector<string> *v = new vector<string>(3);

	(*v)[0] = "c++";
	(*v)[1] = "php";
	(*v)[2] = "java";

	for (auto s : *v)
		cout << s << endl;

	delete v;

	return 0;
}


/*
run:

c++
php
java

*/

 

70+ SQL courses for beginners and professionals

Answer 6

#include <iostream>
#include <vector>
  
void printVector(std::vector<int> const &v) {
    for (auto const &n: v) {
        std::cout << n << " ";
    }
}
   
int main ()
{
    std::vector<int> v = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
   
    printVector(v);
     
    int *p = v.data();
 
    *p = 99;
    ++p;
    *p = 7513;
    *(p + 2) = 238;
    p[5] = 8942; 
     
    std::cout << std::endl;
     
    printVector(v);
}
   
   
   
/*
run:
   
1 2 3 4 5 6 7 8 9 
99 7513 3 238 5 6 8942 8 9 
    
*/

 

70+ SQL courses for beginners and professionals