EN CSharp Keyword unchecked

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C#: unchecked

Handbook C# · Practical Guide

Disables checking for matching integer overflows; the result is truncated to the type range.

Simple example (Example.cs)

Save this example separately as Example.cs. Run it independently of the other examples on this page.

Example.cs:

// PROJECT-EXAMPLE
int value = int.MaxValue;
System.Console.WriteLine(unchecked(value + 1));

Result:

-2147483648

Syntax

unchecked(expression) / unchecked { ... }

Example 1: simple form

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.IO;
using System.Runtime.InteropServices;
using System.Runtime.CompilerServices;

public static class Program
{
    public static async Task Main(string[] args)
    {
        int maximum = int.MaxValue;
        try { Console.WriteLine(checked(maximum + 1)); } catch (OverflowException) { Console.WriteLine("Overflow"); }
    }
}

Example 2: another practical form

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using System.IO;
using System.Runtime.InteropServices;
using System.Runtime.CompilerServices;

public static class Program
{
    public static async Task Main(string[] args)
    {
        int maximum = int.MaxValue;
        int wrapped = unchecked(maximum + 1);
        Console.WriteLine(wrapped);
    }
}

Official source: Microsoft Learn.