remove element from vector by value c++ code example

Example 1: remove value from vector c++

#include <algorithm>
#include <vector>

// using the erase-remove idiom

std::vector<int> vec {2, 4, 6, 8};
int value = 8 // value to be removed
vec.erase(std::remove(vec.begin(), vec.end(), value), vec.end());

Example 2: c++ vector erase by value

//wiki - erase-remove idiom
// Use g++ -std=c++11 or clang++ -std=c++11 to compile.

#include <algorithm>  // remove and remove_if
#include <iostream>
#include <vector>  // the general-purpose vector container

void Print(const std::vector<int>& vec) {
  for (const auto& i : vec) {
    std::cout << i << ' ';
  }
  std::cout << '\n';
}

int main() {
  // Initializes a vector that holds numbers from 0-9.
  std::vector<int> v = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
  Print(v);

  // Removes all elements with the value 5.
  v.erase(std::remove(v.begin(), v.end(), 5), v.end());
  Print(v);
}

/*
Output:
0 1 2 3 4 5 6 7 8 9
0 1 2 3 4 6 7 8 9

*/

Example 3: how to remove an element from a vector by value c++

std::vector<int> v; 
// fill it up somehow
v.erase(std::remove(v.begin(), v.end(), 99), v.end()); 
// really remove all elements with value 99

Example 4: how to delete an element in vector pair in cpp

#include <iostream>
#include <utility>
#include <vector>

using namespace std;


int main()
{
    vector< pair<int, int> > v;
    int N = 5;
    const int threshold = 2;
    for(int i = 0; i < N; ++i)
        v.push_back(make_pair(i, i));

    int i = 0;
    while(i < v.size())
        if (v[i].second > threshold)
            v.erase(v.begin() + i);
        else
            i++;

    for(int i = 0; i < v.size(); ++i)
        cout << "(" << v[i].first << ", " << v[i].second << ")\n";

    cout << "Done" << endl;
}