EVL Function |  |
Returns a non-empty value from two expressions.
You can use the EVL( ) function to return an appropriate substitute value instead of an empty value, such as False (.F.) or 0, from two expressions. You can also use this functionality to remove empty values from calculations or operations where empty values are not supported or relevant.
The X# Logical value, False (.F.), and the Numeric value of 0 also evaluate to empty.
You can use the EVL( ) function to return an appropriate substitute value instead of an empty value, such as False (.F.) or 0, from two expressions. You can also use this functionality to remove empty values from calculations or operations where empty values are not supported or relevant.
The X# Logical value, False (.F.), and the Numeric value of 0 also evaluate to empty.
Namespace: XSharp.VFP
Assembly: XSharp.VFP (in XSharp.VFP.dll) Version: 2.19
SyntaxRequest Example
View Source
Character, Date, DateTime, Numeric, Currency, Logical, Object. EVL( ) returns eExpression1 if it does not evaluate to an empty value, otherwise, it returns eExpresssion2.
Parameters
- eExpression1
- Type: Usual
Specifies an expression. eExpression1 can be any data type. - eExpression2
- Type: Usual
Specifies an expression. eExpression1 can be any data type.
Return Value
Type: UsualCharacter, Date, DateTime, Numeric, Currency, Logical, Object. EVL( ) returns eExpression1 if it does not evaluate to an empty value, otherwise, it returns eExpresssion2.
Examples
The following examples create the memory variables, ,
which contains an empty Date value, and ,
which contains an empty Numeric value, 0.
When performing EVL( ) with, EVL( ) returns an empty string ("")
when evaluating and an empty string,
and code"None"/code when evaluating and .
When performing EVL( ) with glEmptyNum, EVL( ) returns an empty string when evaluating glEmptyNum and an empty string,
and "Empty" when evaluating glEmptyNum and "Empty".
1glEmptyDate1glEmptyNumWhen performing EVL( ) with
1glEmptyNum1glEmptyNum1glEmptyNum1"None"
X#
1STORE { / / } TO glEmptyDate 2? EVL(glEmptyDate,"") 3? EVL(glEmptyDate, "None")
X#
1STORE 0 TO glEmptyNum 2? EVL(glEmptyNum,"") 3? EVL(glEmptyNum, "Empty")
See Also