To remove a value from a vector we must follow the erase-remove idiom, the first step is to find the value that we wish to remove and move it to the front of the container. This is performed using remove which returns an iterator pointing to the new end of the vector, effectively ignoring the removed values. For example:

vector<int> myVec;

myVec.push_back(5);
myVec.push_back(3);
myVec.push_back(4);
myVec.push_back(5);
myVec.push_back(1);
myVec.push_back(5);

//print current vector contents to screen
for (vector<int>::iterator it = myVec.begin(); it !=  myVec.end(); ++it){
 cout << *it << " ";
}
cout << endl;  

Will print this to screen:

5 3 4 5 1 5

If we want to remove all 5 values from myVec we can do this:

int myValue = 5;
vector<int>::iterator NewEnd = remove(myVec.begin(), myVec.end(), myValue);
//NewEnd points to one past the end of the vector with the value 5 removed

for (vector<int>::iterator it = myVec.begin(); it != NewEnd; ++it){
 cout << *it<< " ";

}
cout << endl;  

Which will produce the following data on the screen:

Will print this to screen:

3 4 1

However, the vector’s size has not changed. The removed values are now at the end of the vector and could still be accessed by using myVec.end() instead of NewEnd. So now we will remove the values using erase, to complete the process. If erase is passed 2 iterators it will erase all of the values between those 2 points. So we want to erase every value between NewEnd and myVec.end():

myVec.erase(NewEnd, myVec.end());

We can test that this has worked by attempting to write the whole vector to screen:

for (vector<int>::iterator it = myVec.begin(); it !=  myVec.end(); ++it){
 cout << *it << " ";
}
cout << endl;  

Which gives us a vector completely free of our erased data:

3 4 1

It is also possible to combine this idiom into a one liner:

myVec.erase(remove(myVec.begin(), myVec.end(), myValue), myVec.end());

It should be noted that this code will modify vectors in place so should be used with caution.