How to Remove Element From Vector in C++
-
Use the
erase()Method to Remove Element From Vector in C++ -
Use the
std::erase()Method to Remove Element From Vector in C++ -
Use
std::erase()andstd::remove()to Remove Element From Vector in C++
This article will explain several methods of how to remove an element from a vector in C++.
Use the erase() Method to Remove Element From Vector in C++
The erase() method is a member function of the std::vector class and is capable of a single element of the vector or the range specified as [first, last]. The function returns an iterator following the last removed element. If a single element is removed, as shown in the following code sample, the iterator passed must be dereferenceable.
#include <iostream>
#include <vector>
using std::cin;
using std::cout;
using std::endl;
using std::string;
using std::vector;
void PrintVec(vector<string> &vec) {
for (const auto &item : vec) {
cout << item << "; ";
}
cout << endl;
}
int main() {
vector<string> str_vec = {"array", "vector", "deque", "list", "set",
"map", "stack", "queue", "multimap", "span"};
PrintVec(str_vec);
// DELETE element "set"
auto elem_to_remove = str_vec.begin() + 4;
if (elem_to_remove != str_vec.end()) {
str_vec.erase(elem_to_remove);
}
PrintVec(str_vec);
return EXIT_SUCCESS;
}
Output:
array; vector; deque; list; set; map; stack; queue; multimap; span;
array; vector; deque; list; map; stack; queue; multimap; span;
Use the std::erase() Method to Remove Element From Vector in C++
This std::erase() is a non-member function that takes the range and the value that is compared with every element to delete each time it’s matched. This method might have a disadvantage when a single element needs to be removed, but you can avoid this behavior by passing the second argument by array variable - arr[index]. As demonstrated in the next example, erase only removes the element array.
#include <iostream>
#include <vector>
using std::cin;
using std::cout;
using std::endl;
using std::erase;
using std::string;
using std::vector;
void PrintVec(vector<string> &vec) {
for (const auto &item : vec) {
cout << item << "; ";
}
cout << endl;
}
int main() {
vector<string> str_vec = {"array", "vector", "deque", "list", "set",
"map", "stack", "queue", "multimap", "span"};
PrintVec(str_vec);
// DELETE elemen "array"
erase(str_vec, str_vec[0]);
PrintVec(str_vec);
return EXIT_SUCCESS;
}
Output:
array; vector; deque; list; set; map; stack; queue; multimap; span;
vector; deque; list; set; map; stack; queue; multimap; span;
Use std::erase() and std::remove() to Remove Element From Vector in C++
This method is called Erase-remove idiom, and it removes every element that is equal to a certain value or satisfies a criterion from a given range. Notice that this solution has some exceptional features, like - it can’t be used with containers that return const_iterator.
#include <algorithm>
#include <iostream>
#include <vector>
using std::cin;
using std::cout;
using std::endl;
using std::erase;
using std::string;
using std::vector;
void PrintVec(vector<string> &vec) {
for (const auto &item : vec) {
cout << item << "; ";
}
cout << endl;
}
int main() {
vector<string> str_vec = {"map", "vector", "deque", "list", "set",
"map", "stack", "queue", "map", "span"};
PrintVec(str_vec);
// DELETES all elements with value "map"
str_vec.erase(std::remove(str_vec.begin(), str_vec.end(), "map"),
str_vec.end());
PrintVec(str_vec);
return EXIT_SUCCESS;
}
Output:
map; vector; deque; list; set; map; stack; queue; map; span;
vector; deque; list; set; stack; queue; span;
Founder of DelftStack.com. Jinku has worked in the robotics and automotive industries for over 8 years. He sharpened his coding skills when he needed to do the automatic testing, data collection from remote servers and report creation from the endurance test. He is from an electrical/electronics engineering background but has expanded his interest to embedded electronics, embedded programming and front-/back-end programming.
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