Complex LINQ query
Considering this structure...
List<IEnumerable<KeyValuePair<String, String>>>
How would you write a LINQ query for the following pseudo-code...
SELECT
/* Count of how many [KeyValuePair] exists in [List] */
FROM
[List]
WHERE
[KeyValuePair].Key == "foo"
AND Int32.Parse([KeyValuePair].Value.Replace(".", "")) > 10
...?
Update
The result of the above query, run aginst the list below, should be 6 (six)...
var list = new List<IEnumerable<KeyValuePair<String, String>>>
{
new []
{
new KeyValuePair<String, String>("foo", "1.1"),
new KeyValuePair<String, String>("foo", "1.2"),
new KeyValuePair<String, String>("foo", "1.3")
},
new []
{
new KeyValuePair<String, String>("foo", "0.1"),
new KeyValuePair<String, String>("foo", "0.2"),
new Key开发者_Python百科ValuePair<String, String>("foo", "0.3")
},
new []
{
new KeyValuePair<String, String>("foo", "2.1"),
new KeyValuePair<String, String>("foo", "2.2"),
new KeyValuePair<String, String>("foo", "2.3")
}
};
I get 6 from this...
var result = list.Sum(item=>item.Count(kp=>kp.Key == "foo" && int.Parse(kp.Value.Replace(".",String.Empty))>10));
var result = list.SelectMany(ary =>aryx).Count(item => item.Key == "Foo" && Int32.Parse(item.Value.Replace(".", "")) > 10);
Although I'm guessing you're replacing the "." because you want to get rid of thousands separators, so You might want: Int32.Parse(item.Value, NumberStyles.AllowThousands, CultureInfo.CurrentCulture)
making sure you have the Current Culture set appropriately.
I might write it for clarity like this:
var result = list.SelectMany(ary => ary)
.Where(item => item.Key.Equals("Foo", StringComparison.CurrentCulture))
.Select(item =>
Int32.Parse(item.Value.Replace(".", ""))
.Count(value=> value> 10);
Comprehension syntax might look like:
var q = from @array in list
from kvp in array
where kvp.Key.Equals("Foo", StringComparison.CurrentCulture)
select .Parse(item.Value.Replace(".", ""));
var result = q.Count(value => value > 10);
精彩评论