Unity for loop: (List) Argument out of range

Question

I am attempting to copy the contents of one list into another. On the first iteration I get an "Argument out of range" error.

static List<Building> SaveBuildings(List<Building> buildings)
{
    if (buildings.Count == 0)
        return null;
    Debug.Log("Save Buildings Count: " + buildings.Count);
    List<Building> records = new List<Building>();
    for (int i = 1; i < buildings.Count; i++)
    {
        Debug.Log("i: " + buildings[i].name);
        records[i] = buildings[i].GetRecord();
    }
    return records;
}

The offending line is: records[i] = buildings[i].GetRecord();

This code "Debug.Log("Save Buildings Count: " + buildings.Count);" shows that the list is not empty. The following code "List records = new List();" instantiates a new list to be used.

My understanding is that everything should work well, but when I run the code this line fires "Debug.Log("i: " + buildings[i].name);" and then the error.

I've changed "int i" to be "0" and "i < buildings.Count" to "i <= buildings.Count" with i being 1 and 0. Same results.

I need fresh eyes to find the error lol thank you for your help

Answer 1

The issue is that records is empty. Are you intentionally skipping the first building? If not, I think this is what you want:

for (int i = 0; i < buildings.Count; i++)
{
    records.Add(buildings[i].GetRecord());
}