Loop through Hashtable

Questions & Answers
1

I have a hashtable and I want to loop through the keys to find one that matches my timer and then debug.log that value - I have this part working. How can I loop through it to find the next lowest key that matches the time if there is no exact match?

I’m currently using : if (myHashtable.ContainsKey(currentTime))

2

foreach (time in myHashTable)
{
if (time < …

3

You can’t guarantee a Hashtable will keep keys sorted in a sensible order (depending on what your key type is). You’d have better luck keeping a separate structure (which contains just the keys used in your Hashtable) where the values are known to be in order (give [SortedList][1] a try). Then you can go through the sorted list and find the “closest without going over” key with something similar to the following:

//Handle some edge cases
if (sortedKeyList.Count == 0 || currentTime < sortedKeyList[0] || currentTime > sortedKeyList[sortedKeyList.Count - 1])
{
    // Do whatever you'd do if you:
    // have no keys entered,
    // haven't passed the first key,
    // or have past the last key.
}
else
{
    MyKeyClass key;
    for (int i = 1; i < sortedKeyList.Count; i++)
    {
        if (currentTime < sortedKeyList*)*

{
key = sortedKeyList[i - 1];
break; // or if you pull this into a utility function, skip the “key” variable and just return sortedKeyList[i - 1]
}
}
}
Then you can go to myHashtable[key] and use what’s there.
[1]: SortedList Class (System.Collections) | Microsoft Learn