Question

I’m writing a class to store some kind of a table-structure.

Now each column in this table structure has a name, and an index.

Now each row in this column will be looped through, and the data will 90% of the cases be requested using the name of the column rather then the index of it.

So what’s a good data structure to store the columns, so that it can retrieve the index very quickly based upon the name. Right now I’m using a simple string[], but I wonder if there are faster ways to do this.

Parts of the code:

private string[] _columns;
private int _width;

private int getIndex(string columnName)
{
    for (int i = 0; i < _width; i++)
    {
        if (_columns[i] == columnName) return i;
    }
    return -1;
}

The names of the columns will be constant after they’ve been set, and they’re mostly about 10-16 characters long.

Thanks in advance.

Answer 1

Use a Dictionary<string,int> to store the names of the columns against their ID.

Using your example (which misses how _columns is populated):

private IDictionary<string,int> _columns;
private int _width;

private int getIndex(string columnName)
{
    return _columns[columnName];
}