XLISP or

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# or

Type: | - | special form (fsubr)
Source: | - | xlcont.c

## Syntax

(or [expr1 ... ])
  exprN - an expression
  returns - NIL if all expressions evaluate to NIL , otherwise the value of the first non-NIL expression
  Note: evaluation of expressions stops after the first expression that does not evaluate to NIL

## Description

The 'or' special form evaluates a sequence of expressions and returns the effect of a logical 'inclusive-or' operation on the expressions. If all of the expressions are NIL , NIL is returned as the result. Evaluation of the expressions will stop when an expression evaluates to something other than NIL , none of the subsequent expressions will be evaluated. If there are no expressions, 'or' returns NIL as its result.

## Examples

    (or NIL NIL NIL)                    ; returns NIL
    (or NIL T NIL)                      ; returns T
    (or NIL (princ "hi") (princ "ho"))  ; prints  hi  and returns "hi"
    (or T T T)                          ; returns T
    (or)                                ; returns NIL

    (setq a 5)  (setq b 6)              ; set up A and B
    (if (or (< a b) (< b a))            ; if
       (print "not equal")              ;   then
       (print "equal"))                 ;   else
                                        ; prints  "not equal"

See the or special form in the XLISP 2.0 manual.

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Nyquist / XLISP 2.0 - Contents | Tutorials | Examples | Reference