How to set a default parameter for a vector 2019-03-24 15:57发布 站内文章 / C++ 9 0 0

问题:

For example, a class named Table, with its constructor being: Table(string name="", vector <string> mods);

How would I initialize the vector to be empty?

Edit: Forgot to mention this was C++.

回答1:

Table(string name="", vector <string> mods);

if you want vector to be empty inside constructor then

mods.clear();

or

mods.swap(vector<string>());

In case you want as a default parameter:

 Table(string name="", vector<string> mods = vector<string>());

Like any other default parameter.

回答2:

To add to the other answer: If you're using c++11, you can use the universal initialization syntax to shorten the default parameter declaration for a vector to the following:

Table(string name="", vector<string> mods={});