Daniel Simionescu

nameof Operator

For example, we might have the following class with a Deposit method which implements some validation:

internal class BackAccount
{
    public double Balance { get; private set; }

    public void Deposit(double amount)
    {
        if (amount < 0)
        {
            throw new ArgumentOutOfRangeException("amount", amount, "The amount cannot be negative");
        }

        Balance += amount;
    }
}

If, for instance, we want to rename the amount parameter to something else, then the string from the exception is left unchanged which leads to bugs and wrong error messages.

This is where we can use the nameof operator:

internal class BackAccount
{
    public void Deposit(double amount)
    {
        if (amount < 0)
        {
            throw new ArgumentOutOfRangeException(nameof(amount), amount, "The amount cannot be negative");
        }
    }
}

Now, this is not just a string, but a variable name which can be refactored.

Summary

So, in essence the nameof operator is useful when you need to get the name of a variable as a string.

Help me improve this page!

← Null Coalescing Operator →