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=== if ===

See [[http://xelerus.de/index.php?s=functions&function=13|if at Xelerus]]

^ Syntax | (if condition exp1 [exp2]) -> value |
^ Arguments | condition: anything that evaluates to Nil or non-Nil |
^ | exp1: an expression that gets evaluated if 'condition' evaluates to non-Nil (if it is 'true') |
^ | [exp2]: an optional expression that gets evaluated if 'condition' evaluates to Nil (i.e. is 'false') |
^ Returns | value: Whatever the expression that gets invoked returns |
^ Category | [[control structure functions|control structure]] |
^ Description | Basic branching function. Allows executing something only if a certain condition is met. A fundamental thing. |

Unless **condition** explicitly evaluates Nil, the function considers it to be **true**. This works for any **Nil** value in any data type: **error**, **function**, **int32**, **list**, **primitive**, **string**, **struct**, **true**. Even a list containing only **Nil** values is considered **true** since the list itself is not equal to **Nil**. This behavior is equivalent to the following code:
<code>
(neq condition Nil)
</code>

=== Example ===

<code lisp>(if (eq (sysGetNode) "SE")

    (objSendMessage gPlayerShip Nil "We are still in Eridani system")

    (objSendMessage gPlayerShip Nil "We are on the journey to the core")

)
</code>

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