Microsoft KB Archive/114654

{| = ISBLANK Function Provides Additional Null Value Support =
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ID: Q114654

The information in this article applies to:


 * Microsoft FoxPro for Windows, version 2.6
 * Microsoft FoxPro for MS-DOS, version 2.6

SUMMARY
This article describes the new ISBLANK function, which, along with the new BLANK command, provides additional support of null values.

This information can also be found in FoxPro online Help in the "ISBLANK" topic.

MORE INFORMATION
ISBLANK

Determines whether or not an expression is blank. Returns - Logical

ISBLANK returns true (.T.) if the expression is blank, or false (.F.) if the expression is not blank.

APPEND BLANK and BLANK are used to create a blank record. BLANK can also be used to clear data from fields in a record. ISBLANK can determine whether or not a field is blank.

The ISBLANK function is different from the EMPTY function. For example, EMPTY returns true if a character expression contains any combination of nulls, spaces, tabs, carriage returns, or line feeds. ISBLANK returns true only if a character expression contains a null string or spaces.

can be a field in a table/.DBF file, a memory variable or array element, or an expression.

For a field, ISBLANK returns .T. if the field contains the following values:

Type           Contents -

Character      Null string or spaces Numeric        No value (Newly appended blank record or cleared with                   BLANK) Date           Blank date ({  /  /  }) Logical        No value (Newly appended blank record or cleared with                   BLANK) Memo           Empty (no memo contents) General        Empty (no OLE object) For a character or date type memory variable, array element or expression, ISBLANK returns .T. if any of these contain the following values: Type           Contents ---

Character      Null string or spaces Date           Blank date ({  /  /  }) Additional reference words: FoxDos FoxWin 2.60 foxhelp.dbf foxhelp.hlp KBCategory: kbprg KBSubcategory: FxinteropOle
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