// Example 1 Vector of strings
#include <iostream>
#include <string>
#include <vector>
#include <cstdio>
#include <list> //
using namespace std;
int main ()
{
// Example 1
std::vector<std::string> myVector;
char msgname[16];
for (int i = 1; i <= 5; i++)
{
sprintf (msgname, "SWITCH-%d", i);
myVector.push_back (msgname);
}
for (std::vector<std::string>::iterator t = myVector.begin (); t != myVector.end (); ++t)
{
std::cout << *t << std::endl;
}
}
SWITCH-1
SWITCH-2
SWITCH-3
SWITCH-4
SWITCH-5
SWITCH-2
SWITCH-3
SWITCH-4
SWITCH-5
// Example 2
#include <iostream>
#include <string>
int main ()
{
// notes
std::string test1 = "abcde";
char test2[6] = "abcde";
char test3[6];
strcpy (test3, "abcde");
std::cout << "test1: " << test1 << std::endl;
std::cout << "test2: " << test3 << std::endl;
std::cout << "test3: " << test3 << std::endl;
}
test1: abcde
test2: abcde
test3: abcde
// Example 3 structures inside List
#include <iostream>
#include <string>
#include <vector>
#include <cstdio>
#include <list>
//using namespace std;
int main ()
{
// Example 2
struct myData
{
int id;
std::string name;
};
typedef std::list<myData> myDataList;
myDataList objMyDataList;
char switchName[16];
for (int i = 1; i <= 5; i++)
{
sprintf (switchName, "SWITCH-%d", i);
myData objMyData;
objMyData.id=i*100;
objMyData.name = switchName;
objMyDataList.push_back (objMyData);
}
for(std::list<myData>::iterator itt =objMyDataList.begin (); itt!= objMyDataList.end(); itt++){
std::cout << " SW-ID: " << itt->id << " , ";
std::cout << " SW-Name: " << itt->name << std::endl;
}
}
SW-ID: 100 , SW-Name: SWITCH-1
SW-ID: 200 , SW-Name: SWITCH-2
SW-ID: 300 , SW-Name: SWITCH-3
SW-ID: 400 , SW-Name: SWITCH-4
SW-ID: 500 , SW-Name: SWITCH-5
#include <string>
#include <vector>
#include <cstdio>
#include <list>
using namespace std;
struct mystruct {
char name[20];
int grade;
};
int main ()
{
int i;
mystruct names;
list<mystruct> mylist;
for (i=0;i<5;i++) {
strcpy(names.name, "MOH");
names.grade = i+78;
mylist.push_back(names);
}
list<mystruct>::iterator it;
it = mylist.begin();
while (it != mylist.end()) {
cout << "Name: " << it->name << " Grade: " << it->grade << endl;
it++;
}
return 0;
}
Name: MOH Grade: 78
Name: MOH Grade: 79
Name: MOH Grade: 80
Name: MOH Grade: 81
Name: MOH Grade: 82
#include <vector>
#include <iostream>
int main (int argc, char* argv[])
{
std::vector< int > moh;
moh.push_back (10);
moh.push_back (20);
moh.push_back (30);
moh.push_back (40);
moh.push_back (50);
auto iterBegin = moh.begin ();
auto iterNext = std::next (iterBegin, 3);
auto iterPrev = std::prev (iterNext, 2);
auto iterFront= moh.front ();
auto iterNextOut = std::next (iterBegin, 500); // out of range returns random number (sometimes zero)
auto iterPrevOut = std::prev (iterBegin, 500); // out of range returns random number
auto iterEnd = moh.end (); // does NOT return ZERO
auto iterBack = moh.back (); // returns the last element in the vector
std::cout << " iterBegin = " << *iterBegin << std::endl;
std::cout << " iterNext = " << *iterNext << std::endl;
std::cout << " iterPrev = " << *iterPrev << std::endl;
std::cout << "\n iterFront = " << iterFront << std::endl;
std::cout << "\n iterNextOut = " << *iterNextOut << std::endl;
std::cout << " iterPrevOut = " << *iterPrevOut << std::endl;
std::cout << "\n iterE = " << *iterEnd << std::endl;
std::cout << " iterB = " << iterBack << std::endl;
}
iterBegin = 10
iterNext = 40
iterPrev = 20
iterFront = 10
iterNextOut = 0
iterPrevOut = 65537
iterE = 32767
iterB = 50
// Example 9 Erasing from list
#include <iostream>
#include <list>
int main ()
{
struct PakcetsToSend
{
unsigned int pktId;
};
typedef std::list<PakcetsToSend> PakcetsToSendList;
PakcetsToSendList sentPakcetsList;
// set some values:
for (int i = 1; i <= 5; ++i)
{
PakcetsToSend pktSent;
pktSent.pktId = 10 * i;
sentPakcetsList.push_back (pktSent);
}
std::cout << "mylist contains:\n";
std::list<PakcetsToSend>::iterator iter;
iter = sentPakcetsList.begin ();
int index = 0;
while (iter != sentPakcetsList.end ())
{
std::cout << ++index << " SQN: " << iter->pktId << "\n";
iter++;
}
std::list<PakcetsToSend>::iterator it;
it = sentPakcetsList.begin();
while (it != sentPakcetsList.end()) {
if (it->pktId == 30) {
std::cout << "ackArrivedFreeBuffer erase : " << it->pktId << "\n";
it = sentPakcetsList.erase(it);
break;
} else {
std::cout << " SQN: " << it->pktId << "\n";
it++;
}
}
std::cout << "\nmylist contains:\n";
std::list<PakcetsToSend>::iterator iterrr;
iterrr = sentPakcetsList.begin ();
int index2 = 0;
while (iterrr != sentPakcetsList.end ())
{
std::cout << ++index2 << " SQN: " << iterrr->pktId << "\n";
iterrr++;
}
return 0;
}
mylist contains:
1 SQN: 10
2 SQN: 20
3 SQN: 30
4 SQN: 40
5 SQN: 50
SQN: 10
SQN: 20
ackArrivedFreeBuffer erase : 30
mylist contains:
1 SQN: 10
2 SQN: 20
3 SQN: 40
4 SQN: 50
// Example 10 Random number generator using seeds
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int seedValue = 500;
for (int i = 0; i < 5; i++) {
srand(seedValue); // wrong-- this should be called just once
int selected = ((rand() % 4));
std::cout << selected << "\n";
}
}
??? WRONG
0
0
0
0
0
The correct code is as follows:
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int seedValue = 500;
srand(seedValue); // get same values each run as we use same seedValue
// Example 12 exponential_distribution
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int seedValue = 100;
int arrivalRate = 1;
// srand(seedValue);
std::mt19937 PRNG;
std::exponential_distribution<double> expDistribution;
PRNG = std::mt19937(seedValue);
expDistribution = std::exponential_distribution<double> (arrivalRate);
for (int i = 0; i < 5; i++) {
double getExp = expDistribution.operator()(PRNG);
std::cout << getExp << "\n";
}
}
0.531107
0.747355
0.160879
0.170446
// Example 13 Function pointer
#include <iostream>
using namespace std;
int add(int a, int b){ return a+b; }
void hi(){ cout << "Hi there! \n"; }
void hello(char* name){ cout << "Hello Mr. " << name << "\n"; }
int main ()
{
int (*funptr)(int,int);
funptr = add;
cout << funptr(2,4) << "\n";
void (*funptr2)();
funptr2 = hi;
funptr2();
void (*funptr3)(char*);
funptr3 = hello;
char *name ="Moh";
funptr3(name) ;
return 0;
}
6
Hi there!
Hello Mr. Moh
// Example 14 callback
#include <iostream>
using namespace std;
int addFun(int a, int b , int (*funptr)(int,int)){
return a + b + funptr(a,b) ; // funptr(a,b) is callback to add
}
int add(int a, int b){ return a+b; }
int main (int argc, char** argv)
{
cout << " result = " << addFun(5,5,add) << "\n";
return 0;
}
result = 20
// Example 15 callback
this is the hi function
// Example 16
ampersand
// Example 17
SW-ID: 200 , SW-Name: SWITCH-2
SW-ID: 300 , SW-Name: SWITCH-3
SW-ID: 400 , SW-Name: SWITCH-4
SW-ID: 500 , SW-Name: SWITCH-5
// Example 4 structures inside STL List
#include <iostream>#include <string>
#include <vector>
#include <cstdio>
#include <list>
using namespace std;
struct mystruct {
char name[20];
int grade;
};
int main ()
{
int i;
mystruct names;
list<mystruct> mylist;
for (i=0;i<5;i++) {
strcpy(names.name, "MOH");
names.grade = i+78;
mylist.push_back(names);
}
list<mystruct>::iterator it;
it = mylist.begin();
while (it != mylist.end()) {
cout << "Name: " << it->name << " Grade: " << it->grade << endl;
it++;
}
return 0;
}
Name: MOH Grade: 78
Name: MOH Grade: 79
Name: MOH Grade: 80
Name: MOH Grade: 81
Name: MOH Grade: 82
// Example 5 map – advance
#include<iostream>
#include<map>
using namespace std;
int main ()
{
std::map <int, int> moh;
for (int i = 0; i < 5; i++) { moh[i] = 10 * i; }
auto iter = moh.begin ();
while (iter != moh.end ())
{
std::cout << "index: " << iter->first << ", value: " << iter->second << "\n";
++iter;
}
auto it=moh.begin ();
std::advance(it, 2);
std::cout << "\nindex: " << it->first << ", value: " << it->second << std::endl;
}
index: 0, value: 0
index: 1, value: 10
index: 2, value: 20
index: 3, value: 30
index: 4, value: 40
index: 2, value: 20
// Example 6 map – erase
#include<iostream>
#include<map>
using namespace std;
int main ()
{
std::map <int, int> moh;
for (int i = 0; i < 5; i++)
{
moh[i] = 10 * i;
}
auto iter = moh.begin ();
while (iter != moh.end ())
{
std::cout << "index: " << iter->first << ", value: " << iter->second << "\n";
++iter;
}
std::cout << "\nadvance iter to map2: " << "\n";
auto it = moh.begin ();
std::advance (it, 2);
std::cout << "index: " << it->first << ", value: " << it->second << "\n\n";
moh.erase (it);
std::cout << "erase map 2: " << "\n";
auto iterrr = moh.begin ();
while (iterrr != moh.end ())
{
std::cout << "index: " << iterrr->first << ", value: " << iterrr->second << "\n";
++iterrr;
}
}
index: 0, value: 0
index: 1, value: 10
index: 2, value: 20
index: 3, value: 30
index: 4, value: 40
advance iter to map2:
index: 2, value: 20
erase map 2:
index: 0, value: 0
index: 1, value: 10
index: 3, value: 30
index: 4, value: 40
// Example 7 vector – erase
#include <iostream>
int
main (int argc, char* argv[])
{
std::vector< int > moh;
moh.push_back (1);
moh.push_back (2);
moh.push_back (3);
moh.push_back (4);
moh.push_back (5);
moh.push_back (6);
for (auto iter = moh.begin (); iter != moh.end (); ++iter)
{
if (*iter == 6) { moh.erase (iter); }
std::cout << " vec = " << *iter << std::endl;
}
}
The correct way of using erase() is as follows,
#include <vector>
#include <iostream>
int
main (int argc, char* argv[])
{
std::vector< int > moh;
moh.push_back (1);
moh.push_back (2);
moh.push_back (3);
moh.push_back (4);
moh.push_back (5);
moh.push_back (6);
for (auto iter = moh.begin (); iter != moh.end (); )
{
if (*iter == 6)
{
moh.erase (iter);
} else {
++iter;
}
}
for (auto it = moh.begin (); it != moh.end (); ++it)
{
std::cout << " vec = " << *it << std::endl;
}
}
vec = 1
vec = 2
vec = 3
vec = 4
vec = 5
// Example 8 INT vector – Next Prev Back End Begin
end() returns the iterator (not an element) past-the-end of the vector.
#include<iostream>
#include<map>
using namespace std;
int main ()
{
std::map <int, int> moh;
for (int i = 0; i < 5; i++) { moh[i] = 10 * i; }
auto iter = moh.begin ();
while (iter != moh.end ())
{
std::cout << "index: " << iter->first << ", value: " << iter->second << "\n";
++iter;
}
auto it=moh.begin ();
std::advance(it, 2);
std::cout << "\nindex: " << it->first << ", value: " << it->second << std::endl;
}
index: 0, value: 0
index: 1, value: 10
index: 2, value: 20
index: 3, value: 30
index: 4, value: 40
index: 2, value: 20
// Example 6 map – erase
#include<iostream>
#include<map>
using namespace std;
int main ()
{
std::map <int, int> moh;
for (int i = 0; i < 5; i++)
{
moh[i] = 10 * i;
}
auto iter = moh.begin ();
while (iter != moh.end ())
{
std::cout << "index: " << iter->first << ", value: " << iter->second << "\n";
++iter;
}
std::cout << "\nadvance iter to map2: " << "\n";
auto it = moh.begin ();
std::advance (it, 2);
std::cout << "index: " << it->first << ", value: " << it->second << "\n\n";
moh.erase (it);
std::cout << "erase map 2: " << "\n";
auto iterrr = moh.begin ();
while (iterrr != moh.end ())
{
std::cout << "index: " << iterrr->first << ", value: " << iterrr->second << "\n";
++iterrr;
}
}
index: 0, value: 0
index: 1, value: 10
index: 2, value: 20
index: 3, value: 30
index: 4, value: 40
advance iter to map2:
index: 2, value: 20
erase map 2:
index: 0, value: 0
index: 1, value: 10
index: 3, value: 30
index: 4, value: 40
// Example 7 vector – erase
vec.erase(iter) always returns the next valid iterator, if you erase the last element it will point to .end(). At the end of the loop ++iter is always called, so you increment .end() which is not allowed.
Here is an example of wrong usage of .erase():
#include <vector>#include <iostream>
int
main (int argc, char* argv[])
{
std::vector< int > moh;
moh.push_back (1);
moh.push_back (2);
moh.push_back (3);
moh.push_back (4);
moh.push_back (5);
moh.push_back (6);
for (auto iter = moh.begin (); iter != moh.end (); ++iter)
{
if (*iter == 6) { moh.erase (iter); }
std::cout << " vec = " << *iter << std::endl;
}
}
The correct way of using erase() is as follows,
#include <vector>
#include <iostream>
int
main (int argc, char* argv[])
{
std::vector< int > moh;
moh.push_back (1);
moh.push_back (2);
moh.push_back (3);
moh.push_back (4);
moh.push_back (5);
moh.push_back (6);
for (auto iter = moh.begin (); iter != moh.end (); )
{
if (*iter == 6)
{
moh.erase (iter);
} else {
++iter;
}
}
for (auto it = moh.begin (); it != moh.end (); ++it)
{
std::cout << " vec = " << *it << std::endl;
}
}
vec = 1
vec = 2
vec = 3
vec = 4
vec = 5
// Example 8 INT vector – Next Prev Back End Begin
end() returns the iterator (not an element) past-the-end of the vector.
back() returns a reference to the last element. It has a counterpart front() as well.
Don't use * with back() and front().
#include <vector>
#include <iostream>
int main (int argc, char* argv[])
{
std::vector< int > moh;
moh.push_back (10);
moh.push_back (20);
moh.push_back (30);
moh.push_back (40);
moh.push_back (50);
auto iterBegin = moh.begin ();
auto iterNext = std::next (iterBegin, 3);
auto iterPrev = std::prev (iterNext, 2);
auto iterFront= moh.front ();
auto iterNextOut = std::next (iterBegin, 500); // out of range returns random number (sometimes zero)
auto iterPrevOut = std::prev (iterBegin, 500); // out of range returns random number
auto iterEnd = moh.end (); // does NOT return ZERO
auto iterBack = moh.back (); // returns the last element in the vector
std::cout << " iterBegin = " << *iterBegin << std::endl;
std::cout << " iterNext = " << *iterNext << std::endl;
std::cout << " iterPrev = " << *iterPrev << std::endl;
std::cout << "\n iterFront = " << iterFront << std::endl;
std::cout << "\n iterNextOut = " << *iterNextOut << std::endl;
std::cout << " iterPrevOut = " << *iterPrevOut << std::endl;
std::cout << "\n iterE = " << *iterEnd << std::endl;
std::cout << " iterB = " << iterBack << std::endl;
}
iterBegin = 10
iterNext = 40
iterPrev = 20
iterFront = 10
iterNextOut = 0
iterPrevOut = 65537
iterE = 32767
iterB = 50
// Example 9 Erasing from list
#include <iostream>
#include <list>
int main ()
{
struct PakcetsToSend
{
unsigned int pktId;
};
typedef std::list<PakcetsToSend> PakcetsToSendList;
PakcetsToSendList sentPakcetsList;
// set some values:
for (int i = 1; i <= 5; ++i)
{
PakcetsToSend pktSent;
pktSent.pktId = 10 * i;
sentPakcetsList.push_back (pktSent);
}
std::cout << "mylist contains:\n";
std::list<PakcetsToSend>::iterator iter;
iter = sentPakcetsList.begin ();
int index = 0;
while (iter != sentPakcetsList.end ())
{
std::cout << ++index << " SQN: " << iter->pktId << "\n";
iter++;
}
std::list<PakcetsToSend>::iterator it;
it = sentPakcetsList.begin();
while (it != sentPakcetsList.end()) {
if (it->pktId == 30) {
std::cout << "ackArrivedFreeBuffer erase : " << it->pktId << "\n";
it = sentPakcetsList.erase(it);
break;
} else {
std::cout << " SQN: " << it->pktId << "\n";
it++;
}
}
std::cout << "\nmylist contains:\n";
std::list<PakcetsToSend>::iterator iterrr;
iterrr = sentPakcetsList.begin ();
int index2 = 0;
while (iterrr != sentPakcetsList.end ())
{
std::cout << ++index2 << " SQN: " << iterrr->pktId << "\n";
iterrr++;
}
return 0;
}
mylist contains:
1 SQN: 10
2 SQN: 20
3 SQN: 30
4 SQN: 40
5 SQN: 50
SQN: 10
SQN: 20
ackArrivedFreeBuffer erase : 30
mylist contains:
1 SQN: 10
2 SQN: 20
3 SQN: 40
4 SQN: 50
// Example 10 Random number generator using seeds
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int seedValue = 500;
for (int i = 0; i < 5; i++) {
srand(seedValue); // wrong-- this should be called just once
int selected = ((rand() % 4));
std::cout << selected << "\n";
}
}
??? WRONG
0
0
0
0
0
The correct code is as follows:
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int seedValue = 500;
srand(seedValue); // get same values each run as we use same seedValue
// to get different values use srand(time(NULL))
for (int i = 0; i < 5; i++) {
int selected = ((rand() % 4));
std::cout << selected << "\n";
}
}
// we get same values each run as we use same seedValue
0
1
1
1
2
// Example 11 mt19937: Pseudo-random number generation
Example 11.a
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int arrivalRate = 250;
for (int i = 0; i < 5; i++) {
std::random_device rd;
std::mt19937 rng(rd()); // mt19937: Pseudo-random number generation
std::exponential_distribution<double> exp(arrivalRate);
std::cout << exp.operator()(rng) << "\n";
}
}
We get different output each run:
0.00277043
0.00323534
0.00313602
0.000435214
0.00498137
Example 11.b
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
std::random_device rd;
int arrivalRate = 250;
for (int i = 0; i < 5; i++) {
// take this line out of the for loop
std::mt19937 rng(rd()); // mt19937: Pseudo-random number generation
std::exponential_distribution<double> exp(arrivalRate);
std::cout << exp.operator()(rng) << "\n";
}
}
Same here, we get different output each run.
Example 11.c
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int seedValue = 500;
int arrivalRate = 250;
for (int i = 0; i < 5; i++) {
std::mt19937 rng(seedValue); // mt19937: Pseudo-random number generation
std::exponential_distribution<double> exp(arrivalRate);
std::cout << exp.operator()(rng) << "\n";
}
}
??? WRONG results
0.000310729
0.000310729
0.000310729
0.000310729
0.000310729
int selected = ((rand() % 4));
std::cout << selected << "\n";
}
}
// we get same values each run as we use same seedValue
0
1
1
1
2
// Example 11 mt19937: Pseudo-random number generation
Example 11.a
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int arrivalRate = 250;
for (int i = 0; i < 5; i++) {
std::random_device rd;
std::mt19937 rng(rd()); // mt19937: Pseudo-random number generation
std::exponential_distribution<double> exp(arrivalRate);
std::cout << exp.operator()(rng) << "\n";
}
}
We get different output each run:
0.00277043
0.00323534
0.00313602
0.000435214
0.00498137
Example 11.b
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
std::random_device rd;
int arrivalRate = 250;
for (int i = 0; i < 5; i++) {
// take this line out of the for loop
std::mt19937 rng(rd()); // mt19937: Pseudo-random number generation
std::exponential_distribution<double> exp(arrivalRate);
std::cout << exp.operator()(rng) << "\n";
}
}
Same here, we get different output each run.
Example 11.c
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int seedValue = 500;
int arrivalRate = 250;
for (int i = 0; i < 5; i++) {
std::mt19937 rng(seedValue); // mt19937: Pseudo-random number generation
std::exponential_distribution<double> exp(arrivalRate);
std::cout << exp.operator()(rng) << "\n";
}
}
??? WRONG results
0.000310729
0.000310729
0.000310729
0.000310729
0.000310729
Example 11.d
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int seedValue = 500;
int arrivalRate = 250;
std::mt19937 rng(seedValue); // mt19937: Pseudo-random number generation
for (int i = 0; i < 5; i++) {
std::exponential_distribution<double> exp(arrivalRate);
std::cout << exp.operator()(rng) << "\n";
}
}
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int seedValue = 500;
int arrivalRate = 250;
std::mt19937 rng(seedValue); // mt19937: Pseudo-random number generation
for (int i = 0; i < 5; i++) {
std::exponential_distribution<double> exp(arrivalRate);
std::cout << exp.operator()(rng) << "\n";
}
}
// we get same values each run as we use same seedValue
0.000310729
0.00294197
0.000185657
0.0155086
0.00229585
0.00294197
0.000185657
0.0155086
0.00229585
// Example 12 exponential_distribution
#include <iostream>
#include <sstream>
#include <ctime>
#include <random>
int main()
{
int seedValue = 100;
int arrivalRate = 1;
// srand(seedValue);
std::mt19937 PRNG;
std::exponential_distribution<double> expDistribution;
PRNG = std::mt19937(seedValue);
expDistribution = std::exponential_distribution<double> (arrivalRate);
for (int i = 0; i < 5; i++) {
double getExp = expDistribution.operator()(PRNG);
std::cout << getExp << "\n";
}
}
// we get same values each run as we use same seedValue
1.112170.531107
0.747355
0.160879
0.170446
// Example 13 Function pointer
#include <iostream>
using namespace std;
int add(int a, int b){ return a+b; }
void hi(){ cout << "Hi there! \n"; }
void hello(char* name){ cout << "Hello Mr. " << name << "\n"; }
int main ()
{
int (*funptr)(int,int);
funptr = add;
cout << funptr(2,4) << "\n";
void (*funptr2)();
funptr2 = hi;
funptr2();
void (*funptr3)(char*);
funptr3 = hello;
char *name ="Moh";
funptr3(name) ;
return 0;
}
6
Hi there!
Hello Mr. Moh
// Example 14 callback
#include <iostream>
using namespace std;
int addFun(int a, int b , int (*funptr)(int,int)){
return a + b + funptr(a,b) ; // funptr(a,b) is callback to add
}
int add(int a, int b){ return a+b; }
int main (int argc, char** argv)
{
cout << " result = " << addFun(5,5,add) << "\n";
return 0;
}
result = 20
// Example 15 callback
// Example 16
ampersand
#include <string>
#include <vector>
#include <iostream>
int main(int argc, char *argv[])
{
std::cout << "Have " << argc << " arguments:" << std::endl;
for (int i = 0; i < argc; ++i) {
std::cout << argv[i] << std::endl;
}
std::string my_var(argv[2]);
std::cout << my_var << std::endl;
return 0;
}
g++ test.cpp
./a.out hello1 hello2 hello3
Have 4 arguments:
./a.out
hello1
hello2
hello3
hello2
// Example 17
Pass vector by reference
#include <vector>
#include <iostream>
using namespace std;
void myVecfunction(std::vector<int>& vec) {
// vec.push_back(40);
// vec.pop_back();
delete &vec;
}
int main() {
std::vector<int> *myVec = new std::vector<int>;
myVec->push_back(10);
myVec->push_back(20);
myVec->push_back(30);
std::cout << myVec->size() << " \n";
myVecfunction(*myVec);
return 0;
}
#include <iostream>
using namespace std;
void myVecfunction(std::vector<int>& vec) {
// vec.push_back(40);
// vec.pop_back();
delete &vec;
}
int main() {
std::vector<int> *myVec = new std::vector<int>;
myVec->push_back(10);
myVec->push_back(20);
myVec->push_back(30);
std::cout << myVec->size() << " \n";
myVecfunction(*myVec);
return 0;
}
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