What exactly do you disagree with? My example is different because it demonstrates that variable always has data type cotrary to what Jim said.
I answered original question over a week ago in the Message #1203235

>Your example is different from Jim's. You may have missed the crucial line:
>
>zz = 0
>
>I do not disagree with you lightly (or often) but neither do I disagree often with JimB on database theory and its FoxPro implementation. You both keep us aimed in a good direction.
>
>
>>It's impossible in VFP to create a variable that doesn't have data type assigned to it. If data type is not specified the Logical data type is used as default.
>>

>>zz = Null
>>? TYPE("zz")
>>
>>

>>
>>>This behavior is due to the fact that your variable never had a data type assigned to it while hte fields and scattered variables doi have a data type assigned to them. Try this one;
>>>
>>>

>>>zz = 0
>>>zz = NULL
>>>?str(zz)
>>>

>>>
>>>No error because the data type of zz has been set to numeric so the STR() function works.