Find index of a value in an array

Question

Can linq somehow be used to find the index of a value in an array?

For instance, this loop locates the key index within an array.

for (int i = 0; i < words.Length; i++)
{
    if (words[i].IsKey)
    {
        keyIndex = i;
    }
}

user_697862 · Answer

int index = -1;
index = words.Any (word => { index++; return word.IsKey; }) ? index : -1;