In Python, there are a few different ways we can get the first key/value pair of a dictionary. The easiest way is to use the items() function, convert it to a list, and access the first element. If you only care about getting the first value of a dictionary, you can use the dictionary values() function.
Just use the Linq First() : var first = like. First(); string key = first. Key; Dictionary<string,string> val = first.
Assuming you're using .NET 3.5:
dic.Keys.First();
Note that there's no guaranteed order in which key/value pairs will be iterated over in a dictionary. You may well find that in lots of cases you get out the first key that you put into the dictionaries - but you absolutely must not rely on that. As Skirwan says, there isn't really a notion of "first". Essentially the above will give you "a key from the dictionary" - that's about all that's guaranteed.
(If you don't know whether the dictionary is empty or not, you could use FirstOrDefault
.)
The idea of 'first' doesn't really apply to a dictionary, as there's no ordering on the entries; any insert or remove is allowed to radically change the order of the keys.
Firstly, no, you do not have to enumerate all of the entries — just enumerate the first item:
IEnumerator enumerator = dictionary.Keys.GetEnumerator();
enumerator.MoveNext();
object first = enumerator.Current;
Ideally one would check that the MoveNext() actually succeeded (it returns a bool) otherwise the call to Current may throw.
Please also note that the order of a dicitonary is not specified. This means that the 'first' item may in fact be any key, may be different on subsequent calls (though in practice will not) and will certainly change as items are added and removed from the dictionary.
Seems a bit over the top, but how about
foreach (<Type> k in dic.Keys)
return k;
we can using linq
technology
var key = dic.Take(1).Select(d => d.Key).First()
or we can use another search
var myList = dic.Take(1).Where(d => d.Key.Contains("Heaven")).ToList();
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With