PrimesCounter.razor

<h1>Primes Counter</h1>
<p>@_output</p>
<button class="btn btn-primary" @onclick="CountPrimesSingleThreaded">Single Threaded</button>
<button class="btn btn-primary" @onclick="CountPrimesMultiThreaded">Multi Threaded</button>

@code {
    private string _output = "Not yet executed";

    private void CountPrimesSingleThreaded() {
        int total = 0;
        var sw = System.Diagnostics.Stopwatch.StartNew();
        for (int n = 1; n <= 20_000_000; n++) {
            if (IsPrime(n)) System.Threading.Interlocked.Increment(ref total);
        }
        sw.Stop();
        _output = $"Single Threaded: {total} Primes in {sw.Elapsed}";
    }

     private void CountPrimesMultiThreaded() {
        int total = 0;
        var sw = System.Diagnostics.Stopwatch.StartNew();
        Parallel.For(1, 20_000_001, n => {
            if (IsPrime(n)) System.Threading.Interlocked.Increment(ref total);
        });
        sw.Stop();
        _output = $"Multi Threaded: {total} Primes in {sw.Elapsed}";
    }

    public static bool IsPrime(int number) {
        if ((number % 2) == 0) {
            return number == 2;
        }
        int sqrt = (int)Math.Sqrt(number);
        for (int t = 3; t <= sqrt; t = t + 2) {
            if (number % t == 0) {
                return false;
            }
        }
        return number != 1;
    }
}