See 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 |
| 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:
(neq condition Nil)
(if (eq (sysGetNode) "SE") (objSendMessage gPlayerShip Nil "We are still in Eridani system") (objSendMessage gPlayerShip Nil "We are on the journey to the core") )
Return to Functions list