Can someone explain this code to me ?

Question

I found this code somewhere in sololearn and I just wanted to know how it works.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SoloLearn
{
class Program
{
static void Main(string[] args)
{
string input = Console.ReadLine();
string output = new String(input.Where(c => Char.IsWhiteSpace(c) || Char.IsLetterOrDigit(c)).ToArray());

Console.Write(output);
}
}
}

Answer 1

This is using LINQ and lambda expressions. Basically this is filtering the data. It’s like SQL for collections.

c is just a variable name representing one item in the collection. In this case the colletion is an array of chars.

Simliar to how you’d do this in a foreach statement.
foreach(var c in input)
{...}

https://docs.microsoft.com/en-us/dotnet/api/system.linq.enumerable.where?view=netframework-4.8