Given an array of ints:
int[] testInt = new int[] { 2, 3, 1, 0, 0 };
How can I return an array of ints where each element meets a criteria?
To return all elements are greater than zero, I've tried
int[] temp = testInt.Where(i => testInt[i] > 0).ToArray();
...but this only returns an index with 4 elements of 2, 1, 0, 0.
i is the array element:
int[] temp = testInt.Where(i => i > 0).ToArray();
Where accepts a function (Func<int, bool>) then Where iterates through each element of the array and checks if the condition is true and yields that element. When you write i => the i is the element inside the array. As if you wrote:
foreach(var i in temp)
{
if( i > 0)
// take that i
}
The element you pass on the lambda expression (i on the sample), it is your element on the collection, in the case, the int value. For sample:
int[] temp = testInt.Where(i => i > 0).ToArray();
You also can use by index passing the lambda expression which takes the index on the element. It's not a good pratice, using the element you already have on the scope is the best choice, but for other samples, you could use the index. For sample:
int[] temp = testInt.Where((item, index) => testInt[index] > 0).ToArray();
int[] temp = testInt.Where((item, index) => index < testInt.Length - 1).ToArray(); to copy all but the last element. The question involves criteria with elements, but I think this answer gets bonus points because it points how to deal with criteria with indexes and elements.
Linq specification that allows you to take the element and its index. I hope help you anyway. :)int[] temp = testInt.Where(p=>p>0).ToArray()
