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Marc Clifton wrote:

I think this would make a good interview question!

Closing over the loop variable considered harmful, part one | Fabulous adventures in coding[^]:

UPDATE: We are taking the breaking change. In C# 5, the loop variable of a foreach will be logically inside the loop, and therefore closures will close over a fresh copy of the variable each time. The for loop will not be changed.

// Make sure the sleep statement takes more time then execution of the for block
for (int i = 0; i <= 10; System.Threading.Thread.Sleep(10), i++)
{
   ....
}

Marc Clifton wrote:

I think this would make a good interview question!

function FakeClass() {
  // analogous to a protected variable
  const protectMe = 'When I grow up, I wanna be a class!';  

    // with an anonymous function (kinda like a method)
  this.doSomething = function() {
    // "protectMe" will exist after this function is called
    console.log(protectMe);
  }
}

const sup = new FakeClass();

console.log(sup.protectMe); // not defined
sup.doSomething(); // prints "When I grow up, I wanna be a class!"

int n = i;

In this example c# code "i" can equal 11. can you fix it?

for (int i=0; i <= 10; i++)
{
    var task = Task.Run(async () =>
    {
      var convertResp = await StartTestConvert(i);
      ... other stuff
    });
}

Yes, in the provided code, the variable i is captured by the async lambda expression, which means by the time the async operations inside the lambda complete, the value of i may have changed. To fix this, you need to capture the loop variable correctly. Here's a way to do it:

for (int i = 0; i <= 10; i++)
{
    int current = i; // Capture the current value of i
    var task = Task.Run(async () =>
    {
        var convertResp = await StartTestConvert(current);
        // ... other stuff
    });
}

By capturing the loop variable inside the loop, you ensure that each async operation receives its own copy of the loop variable, preventing the issue where the value of i changes before the async operation completes.