ERR: Not a Numeric Expression

ID: Q120536

2.5x 2.6x 3.00 | 2.00 2.5x 2.6x

WINDOWS        | MS-DOS

• Microsoft Visual FoxPro for Windows, version 3.0
• Microsoft FoxPro for Windows, versions 2.5x, 2.6x
• Microsoft FoxPro for MS-DOS, versions 2.0, 2.5x, 2.6x

SYMPTOMS

You receive the error message "Not a numeric expression" after any of four types of @ ... GETs: buttons, radio buttons, popups, and list boxes.

CAUSE

The FoxPro for Windows "Developer's Guide" for versions 2.5x and 2.6x states on page B-26 that the error "Not a numeric expression" occurs when "An attempt was made to use the SUM command on a non-numeric field."

Another cause for this error message is using a variable that has not been initialized after being declared in a button, radio button, popup, or list box.

RESOLUTION

If a variable is declared, but not initialized, it contains the value of false (.F.). If you then use this variable as the variable for specific types of @ ... GET commands, you will see the "Not a numeric expression" error when you run the code.

The solution is to initialize the variable to a number, or to not declare the variable at all.

MORE INFORMATION

Steps to Reproduce Behavior

1. Place the following code in a program called TEST.PRG:

      CLEAR
      RELEASE ALL
      PUBLIC var1, var2, var3, var4
      DIMENSION myarray(4,1)
      myarray(1,1)="LIST1"
      myarray(2,1)="LIST2"
      myarray(3,1)="LIST3"
      myarray(4,1)="LIST4"

      DEFINE WINDOW main AT 0,0;
         SIZE 17.875,70.286 ;
         FONT "MS Sans Serif", 8 ;
         FLOAT ;
         NOCLOSE ;
         MINIMIZE ;
         SYSTEM

      ACTIVATE WINDOW main

      @ 4.500,3.429 GET var1 ;
         PICTURE "@*HN BUTTON1; BUTTON2" ;
         SIZE 1.625,11.875,0.500 ;
         DEFAULT 1

      @ 6.688,3.429 GET var2 ;
         PICTURE "@*RVN RADIO1; RADIO2" ;
         SIZE 1.063,7.750,0.250 ;
         DEFAULT 1

      @ 1.375,42.857 GET var3 ;
         PICTURE "@^ POPUP1; POPUP2" ;
         SIZE 1.500,15.125 ;
         DEFAULT 1

      @ 4.438,44.714 GET var4 ;
         PICTURE "@&N" ;
         FROM myarray ;
         SIZE 4.500,17.000 ;
         DEFAULT 1

      READ CYCLE

      RELEASE WINDOW main

3. Choose the Ignore button. The error will occur again for each @ ... GET

   defined in the program. If you keep choosing Ignore, the program will
   run through to the end.

Workaround

There are two ways to resolve this problem:

• Remove the line "PUBLIC var1, var2, var3, var4" from the program, and run it again. It should work as expected.

  -or-

• After declaring them, initialize VAR1, VAR2, VAR3, and VAR4 to 1. The program should no longer display the error.

REFERENCES

"Language Reference," version 2.5 (MS-DOS, Windows), pages L3-31 to L3-126

Additional reference words: FoxDos FoxWin VFoxWin 2.00 2.50 2.50a 2.50b 2.60 2.60a 3.00 listbox errmsg KBCategory: KBSubcategory: FxprgGeneral

Keywords          : kberrmsg FxprgGeneral 
Version           : 2.5x 2.6x 3.00 | 2.00 2.5x 2.6x
Platform          : MS-DOS WINDOWS