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lucho
Asked: 2020-11-13 17:35:08 +0800 CST 2020-11-13 17:35:08 +0800 CST

How do you interpret the negation evaluation of a bool method in C#?

  • 772

I have the following method I would like to know how it is interpreted

 if (!existe_producto(ListaProd, item1.codigo))
 {
     item1.Descripcion = item1.codigo + " - " + item1.Descripcion;
     ListaProdx.Add(item1);
 }

   private bool existe_producto(List<Ex_Producto> full_codigo, long codigo)
    {
        try
        {
            bool resp = false;
            foreach (var c in full_codigo)
            {
                if (c.codigox == codigo)
                {
                    resp = true;
                    break;
                }
            }
            return resp;
        }
        catch (Exception ex)
        {
            throw new Exception(ex.Message);
        }

    }

That is, when I evaluate if(bool), that is, if my variable is equal to true, but when I say if(!bool) of a method that returns true or false, as it is read

c#

2 Answers

  1. Best Answer

    Basically it's going to negate what it returns existe_producto(), if it returns a truethen convert it to falsethat will be what theif

    ! Operator (C# Reference)

    • 2

  2. The operator "!" is a negation operator , and what it does is convert one of the booleans ( trueor false) to its respective opposite. In plain language, you could loosely see it as "If x is no such thing, then... ".

    For example, in your case:

    if (!existe_producto(ListaProd, item1.codigo))
 {
     item1.Descripcion = item1.codigo + " - " + item1.Descripcion;
     ListaProdx.Add(item1);
 }

    We assume that the "product_exists()" method returns true (true)if it does exist. Adding the negation operator ("!") is like saying, " If the product doesn't exist, then... ".

    If we were to granulate the code, an equivalent would be something like:

    if(existe_producto(ListaProd, item1.codigo) == false) //Es decir, no existe
{
    ... //tu código
}

    For more information, you can consult the link that Leandro left: ! Operator (C# Reference)

    • 1