How to Remove All Elements of a Dynamically Allocated Array?-CodePudding

So I need to make a function to delete all elements of a dynamically allocated array (found in my program's default constructor), and I am wondering how to do so. A function to remove any element at any index was already provided for me:

template<typename elemType>
void arrayListType<elemType>::removeAt(int location) {
    if (location < 0 || location >= length) {
        cout << "The location of the item to be removed ";
        cout << "is out of range." << endl;
    }
    else {
        for (int i = location; i < length - 1;   i) {
            list[i] = list[i   1];
        }
        --length;
    }
}

Is there any way I can use this method as a way to remove every element to make the size 0?

CodePudding user response：

Given that the elements of list past length are copies of the "live" elements, the simplest way would be to set length to 0.

template<typename elemType>
void arrayListType<elemType>::removeAll() {
    length = 0
}

The naive way of implementing it in terms of removeAt is to remove the first element until there are none left

template<typename elemType>
void arrayListType<elemType>::removeAll() {
    while (length) removeAt(0);
}

However that will do a bunch of unnecessary copying, so it's more effective to remove the last element each time

template<typename elemType>
void arrayListType<elemType>::removeAll() {
    while (length) removeAt(length-1);
}

CodePudding user response：

To just delete the whole array you can use delete[] arr; And if you want to just delete each element, you can do something like this:

for(int i = 0; i < arr_size; i  ){
    delete arr[i];
}