Check null or empty string

Question

I would like to display 'reason not explicited' if the user doesn't fill this field or the user input if he fills it. With this code, I don't understand why but even if I fill the field, it is going to display 'reason not explicited'.

    private string reason;
    public string Reason
    {
        get
        {
            return this.reason;
        }
        set
        {
            if (string.IsNullOrEmpty(this.Reason))
                this.reason = "reason not explicited";
            else this.reason = value;
        }
    }

    [Pure]
    public static bool IsNullOrEmpty(String value) {
        return (value == null || value.Length == 0);
    }

Solution 1

just use value in your setter to handle the correct behavior

set
{
    if (string.IsNullOrEmpty(value))
        this.reason = "reason not explicited";
    else 
        this.reason = value;
}

Solution 2

Because you are checking the property instead of the value.
Your current code sets the value of the property only if it's null or empty.
It should be

    set
    {
        if (string.IsNullOrEmpty(value))
            this.reason = "reason not explicited";
        else this.reason = value;
    }

Or even better:

    set
    {
        this.reason = (string.IsNullOrEmpty(value)) ? "reason not explicited": value;
    }

Solution 3

You have to check value, not this.Reason:

public string Reason
    {
        get
        {
            return this.reason;
        }
        set
        {
            this.reason = string.IsNullOrEmpty(value)
              ? "reason not explicited"
              : value; 
        }
    }

Solution 4

The problem is in this line of code

if (string.IsNullOrEmpty(this.Reason))

When you are trying to get the value of this property, calls it's getter, which returns value of reason field. And this field is not filled with correct value at the moment you are trying to get value of it.

So you should modify your code to check if null or empty string of concrete input value:

if (string.IsNullOrEmpty(value))

View more solutions

Comments

[Dmitry Bychenko]

if (string.IsNullOrEmpty(value)) this.reason = "reason not explicited" ...;

[Igor]

Use some basic client side validation instead to display the appropriate validation message. You can also use property attributes if you are using mvc validation. Do not hard code this into your model logic.

[Myrtle]

Getter should not change values.

[M. Adeel Khalid]

Wrong solution.

[ATC]

I wouldn't recommend it. Getter should return actual value.