LockVariable statement [Revelation On-Line Wiki]

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====== LockVariable statement  ======


 
==== Description ====
 
Locks a BASIC+ variable, so that its data is "coerced" to the proper data type. Used in conjunction with GetPointer.

** NOTE: ** LockVariable has been deprecated in favor of [[ensurevariable|EnsureVariable]].
 
==== Syntax ====
 
**LockVariable** //variable// As //VARIABLE_TYPE//

**//{{{guides:programming:programmers_reference_manual:caution.gif?28x21}}// Caution:**  In the syntax for LockVariable, //VARIABLE_TYPE// is not quoted, although it is a literal. //VARIABLE_TYPE// should not be quoted. Quoting this parameter will cause compiling errors and unpredictable results.
 
==== Parameters ====
 
LockVariable has the following parameters.

^Parameter^Description^
|//Variable//|A BASIC+ variable name. The name cannot be an expression.|
|//VARIABLE_TYPE//|Specifies the type of data referenced by variable.|


LockVariable is required because OpenInsight is an "untyped" language, and variables do not have specific data types, while calls to external routines require the variable to be a specific type. If the return value from GetPointer() is being assigned to a variable, LockVariable the variable first before passing it to GetPointer. 

=== Data Types ===

The following table shows C data types and the corresponding OpenInsight Engine-level data types.

^C data type^OpenEngine-level Data Type^
|Char|String.|
|Byte, Ubyte|Long.|
|Short, Ushort|Long.|
|Long|Long.|
|Float|Double.|
|Double|Double.|
|LPVoid|Long.|
|LPChar|String.|
|LPByte, LPUByte|Long.|
|LPShort, LPUShort|Long.|
|LPLong|Long.|
|LPDouble|Double.|

 
==== See Also ====
 
[[getpointer|GetPointer()]], [[getvalue|GetValue()]]