KNOWLEDGE BASE
Log In    |    Knowledge Base    |    4D Home
Tech Tip: Typing Variables using Compiler Directives
PRODUCT: 4D | VERSION: | PLATFORM:
Published On: June 18, 1999
Your current browser may not allow you to download the asset. We recommend Mozilla Firefox or Google Chrome.
Log In

Type the following code and execute it. You will find that the variable $0 remains undefined. How is this possible?

` Project Method: Method1
C_STRING(255;$0)
$0:="4D."

The variable $0 is a reserved variable that can only be used for returning information to another method. Since I haven't called this method from another method, there is nothing to return and therefore $0 remains undefined. If you were to call Method1 from another method as shown below, you would find $0 functioning as you would expect.

` Project Method: Method2
C_STRING(255;vtName)
vtName:=Method1

You could also have a one line method such as:

` Project Method: Method3
Method1