C#, Operator '??' cannot be applied to operands of type 'decimal' and 'decimal'

is it a decimal? or a decimal

the ?? works with a decimal? but not a decimal since a decimal can never be null.

http://msdn.microsoft.com/en-us/library/ms173224.aspx

The decimal type cannot be null, so the null-coalesce operator makes no sense here. Just set _v1 to value.

Those are value types and cannot be null you can use the Nullable<decimal>

private decimal? _v1;
public decimal? V1
{
    get
    {
        return this._v1;
    }
    set
    {
        this._v1 = value ?? 0M;
    }

}

That is the Null Coalescing Operator. Since decimal can't be null, it has no use with decimal.

You can use a decimal? which can be set to null if you need this functionality:

public decimal? v1 
{
    get 
    {
        return this._v1; 
    }
    set 
    {
        this._v1 = value ?? 0M;
    }
}

Related