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if(n)                                       Tcl Built-In Commands                                      if(n)



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NAME
       if - Execute scripts conditionally

SYNOPSIS
       if expr1 ?then? body1 elseif expr2 ?then? body2 elseif ... ?else? ?bodyN?
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DESCRIPTION
       The  if  command evaluates expr1 as an expression (in the same way that expr evaluates its argument).
       The value of the expression must be a boolean (a numeric value, where 0  is  false  and  anything  is
       true,  or  a string value such as true or yes for true and false or no for false); if it is true then
       body1 is executed by passing it to the Tcl interpreter.  Otherwise expr2 is evaluated as  an  expres-sion expression
       sion  and  if  it is true then body2 is executed, and so on.  If none of the expressions evaluates to
       true then bodyN is executed.  The then and else arguments are optional ``noise words''  to  make  the
       command  easier  to read.  There may be any number of elseif clauses, including zero.  BodyN may also
       be omitted as long as else is omitted too.  The return value from the command is the  result  of  the
       body  script  that was executed, or an empty string if none of the expressions was non-zero and there
       was no bodyN.


SEE ALSO
       expr(n), for(n), foreach(n)


KEYWORDS
       boolean, conditional, else, false, if, true



Tcl                                                                                                    if(n)