in function?

Question

Can you use "in" or contain, to check whether an int is in an array or list without using a for loop?

Answer 1

Use indexOf()
If it returns -1 its not in the array

https://msdn.microsoft.com/en-us/library/system.string.indexof(v=vs.110).aspx

Answer 2

You can use the Contains() method. It works for both Lists and arrays. Here's an example:

int[] arr = new int[] { 1, 2, 3, 4 };
bool b = arr.Contains(3);
Console.WriteLine(b);

List<int> list = new List<int> { 1, 2, 3, 4 };
bool b = list.Contains(3);
Console.WriteLine(b);

Contains returns a boolean. True if the value is within the array/list, and false if it isn't.

Answer 3

And if you are proggraming C# in this decade use method called Contains (it is part of LINQ) which works on all sorts of collections.