Question

for example:- replace 2 with 0 for the following input
Input: string strInput = “21212121”;
Output: “01010101”

How to do it with LINQ. Note: dataType is string.

Answer 1

For your interviewer

string output = new String(input.Select(ch => ch == '2' ? '0' : ch).ToArray());

I think intend was to see if you understand that string could be treated as sequence of characters. Interviews often have questions not related to real-life programming. I personally hate questions about inheritance tree with new modifiers.