声明一个向量返回类型函数并返回向量

Question

I want to write a function that has a return-type as a vector according to codecadmey c++ course I can set the return type as an int,bool,std::string,std::vector to name some but when I try to declare a function that returns a vector I get lots of errors including.

1 - invalid use of template-name 'std::vector' 2 - 'make_arr' was not declared in this scope

#include <iostream>
#include <vector>

using namespace std;


std::vector make_arr(int num ){
    std::vector<int> arr(num);
    for (int i=0; i < num; i++){
        cin >> arr[i];
    }

    for (int i=0; i < arr.size(); i++){
        cout << arr[i];
    }
}





int main(){
    int num=0;
    cin >> num;
    make_arr(num);
    cout << "done\n";
}

Answer 1

std::vector<int> make_arr(int num ){

This fixes the first issue which is causing the second issue. You have a 3rd issue that you never actually return the vector, which you just need to do by doing

return arr;

Then you should do something with the returned vector, but that won't cause any compilation issues if not