short instruction

hello,

I'm new to c sharp and I have a small problem.
I have an array A of 4 elements.
I want to check if an element e is part of the array, and if so return the index of this element (which is always unique) and assign it to a variable v.
What's the easiest and shortest way of doing this, in one line if possible ?
Something like var v = A.findNext(a=> a == e);
The problem is that A.findNext doesn't exist, and A.contains only returns a boolean.

Thanks.

Code:

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int myIndex = Array.IndexOf(myArray, myValue);

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There are multiple ways.

Code:

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// List of Integers
var A = List<int>;

//Find position of the number 42
int myIndex = A.IndexOf(42);

//or

int myIndex = A.FindIndex( (i) => i == 42 );

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