# How do I assign a diffeent vale to Null in mobile

I am trying to set a decimal field to -999 for null values in order to allow me to use zero as a valid entry.

I know this is possible in the web-app but cannot do it for mobile

Hi, friend!

The use the If node is helping? You can use this on input values. Something like

If(DecimalValue = 0, -999, DecimalValue )

Or you can set the default value to -999 and it will replace the null value.

Lenon Manhães wrote:

Hi, friend!

The use the If node is helping? You can use this on input values. Something like

If(DecimalValue = 0, -999, DecimalValue )

Or you can set the default value to -999 and it will replace the null value.

Hi Lenon,

Thank you for your help here. I'm afraid this isn't working for what I need. I have a numeric field which needs to have the ability to be set to zero, one or two etc. What I need is for Null to be set to an unwanted value (e.g. -999) but I do not want it to be visible. If I set the default value it shows as -999 on the phone screen before you enter any value.

Do you know how I can make null/default show as space?

I'm afraid I don't get it yet.

What you want is, if the user type some negative value (e.g -999 or -1), set 0 to the input field?

If yes, you could use an OnChange screen action wich verifies the value. If the value is -999 or -1, use the assign to set 0 to the inpiut field.

Hi,

At present if the 'number of days' field has a default value of zero, it will appear on the phone screen as blank. What I want is for a separate input field to be visible if the number of days is zero, one, two or three. However, setting the visibility to  > -1 and < 4 reads the Null as zero. Meaning that the second field is visible without having any value entered.

Setting the default to -999 and using the following :-

`Box.dates_window_days <> NullIdentifier() and Box.dates_window_days < 4`

shows -999 as the visible value.

What I need, is for the screen value to be blank if null, zero if zero, one if one etc. Null cannot be the same value as zero, as the second field should not be seen until a value is entered, and then only if it is 0,1,2, or 3.

I hope this makes more sense