Find integer in list with Array.exists()

Question

I have an array of integers:

var a = [1,2,3,4];

How can I find out if a number such as the number 1 exists in this array without doing a for loop?

I saw that C# has an Array.Exists(T) method but I am not sure how to use it. If this is a good way to do it then I would appreciate some advice.

Amir Popovich · Accepted Answer · 2014-12-14 12:42:50Z

3

Better to user Contains or Any but you asked for Exists so:

int[] arr = {1,2,3,4};

Exists:

bool a = Array.Exists(arr, elem => elem == 1); // true
bool b = Array.Exists(arr, elem => elem == 5); // false

Contains:

  bool a = arr.Contains(1); // true
  bool b = arr.Contains(5); // false

Any:

 bool a = arr.Any(elem => elem == 1); // true
 bool b = arr.Any(elem => elem == 5); // false

answered Dec 14, 2014 at 12:36

Amir Popovich

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Comments

Sergey Kalinichenko · Accepted Answer · 2014-12-14 12:36:08Z

1

Since C# arrays can be used in LINQ expressions, you can do this:

bool hasOne = a.Any(n => (n == 4));

You need to add using System.Linq in order for this to compile.

answered Dec 14, 2014 at 12:36

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Sajeetharan · Accepted Answer · 2014-12-14 12:38:50Z

1

Using Linq Contains you can check for the existence of int,

var intVar = 1;
var exists = a.Contains(intVar);

answered Dec 14, 2014 at 12:33

Sajeetharan

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@marifemac the best way to check it is to try it yourself! dotnetfiddle.net/0PR3iT