Difference between revisions of "ISSET()"
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==Purpose== | ==Purpose== | ||
| − | + | Function to check whether a variable exists | |
==Syntax== | ==Syntax== | ||
| − | + | ISSET(<variable name>) | |
==See Also== | ==See Also== | ||
| − | + | [[DECLARE]], [[DIMENSION]], [[LOCAL]], [[PARAMETERS]], [[PRIVATE]], [[PUBLIC]], [[RELEASE]], [[STATIC]], [[STORE]], [[TYPE()]], [[UNSET()]] | |
==Description== | ==Description== | ||
| − | + | The ISSET() function can be used to check whether a variable exists. ISSET() will return .T. (true) if the variable named <variable name> exists and .F. (false) if it does not exist. Variables can be formally declared ([[PUBLIC]], [[PRIVATE]] etc.) or automatically created when they are assigned a value. | |
==Example== | ==Example== | ||
<code lang="recital"> | <code lang="recital"> | ||
| − | + | if isset(m_var) | |
| + | // m_var exists | ||
| + | endif | ||
</code> | </code> | ||
==Products== | ==Products== | ||
| + | Recital, Recital Server | ||
[[Category:Documentation]] | [[Category:Documentation]] | ||
[[Category:Functions]] | [[Category:Functions]] | ||
| + | [[Category:Memory Variables]] | ||
| + | [[Category:Memory Variables Functions]] | ||
Revision as of 17:08, 30 October 2009
Purpose
Function to check whether a variable exists
Syntax
ISSET(<variable name>)
See Also
DECLARE, DIMENSION, LOCAL, PARAMETERS, PRIVATE, PUBLIC, RELEASE, STATIC, STORE, TYPE(), UNSET()
Description
The ISSET() function can be used to check whether a variable exists. ISSET() will return .T. (true) if the variable named <variable name> exists and .F. (false) if it does not exist. Variables can be formally declared (PUBLIC, PRIVATE etc.) or automatically created when they are assigned a value.
Example
if isset(m_var) // m_var exists endif
Products
Recital, Recital Server
