ListUtility.BinarySearchForKey<TItem,TKey> method

Searches a sorted list for a key via binary search. The list must be sorted by the ordering in the passed comparison.

public static int BinarySearchForKey<TItem, TKey>(IReadOnlyList<TItem> list, TKey key, 
    Func<TItem, TKey, int> compare, out int index)

parameter	description
list	The sorted list to search.
key	The key to search for.
compare	The comparison.
index	Returns the first index at which the key can be found. If the return value is zero, indicating that key was not present in the list, then this returns the index at which key could be inserted to maintain the sorted order of the list.

Return Value

The number of keys equal to key that appear in the list.