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RedHat 9 (Linux i386) - man page for foreach (redhat section n)

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

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NAME
       foreach - Iterate over all elements in one or more lists

SYNOPSIS
       foreach varname list body
       foreach varlist1 list1 ?varlist2 list2 ...? body
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DESCRIPTION
       The  foreach  command implements a loop where the loop variable(s) take on values from one
       or more lists.  In the simplest case there is one loop variable, varname,  and  one  list,
       list,  that  is a list of values to assign to varname.  The body argument is a Tcl script.
       For each element of list (in order from first to last), foreach assigns	the  contents  of
       the element to varname as if the lindex command had been used to extract the element, then
       calls the Tcl interpreter to execute body.

       In the general case there can be more than one value list (e.g.,  list1	and  list2),  and
       each  value  list  can  be  associated  with  a list of loop variables (e.g., varlist1 and
       varlist2).  During each iteration of the loop the variables of each varlist  are  assigned
       consecutive  values  from  the  corresponding list.  Values in each list are used in order
       from first to last, and each value is used exactly once.  The total number of loop  itera-
       tions  is large enough to use up all the values from all the value lists.  If a value list
       does not contain enough elements for each of its loop variables in each	iteration,  empty
       values are used for the missing elements.

       The  break  and continue statements may be invoked inside body, with the same effect as in
       the for command.  Foreach returns an empty string.

EXAMPLES
       The following loop uses i and j as loop variables to iterate over pairs of elements  of	a
       single list.  set x {} foreach {i j} {a b c d e f} {
	   lappend  x  $j  $i } # The value of x is "b a d c f e" # There are 3 iterations of the
       loop.

       The next loop uses i and j to iterate over two lists in parallel.  set x {} foreach i {a b
       c} j {d e f g} {
	   lappend  x  $i $j } # The value of x is "a d b e c f {} g" # There are 4 iterations of
       the loop.

       The two forms are combined in the following example.  set x {} foreach i {a b c} {j k}  {d
       e f g} {
	   lappend  x  $i  $j $k } # The value of x is "a d e b f g c {} {}" # There are 3 itera-
       tions of the loop.

SEE ALSO
       for(n), while(n), break(n), continue(n)

KEYWORDS
       foreach, iteration, list, looping

Tcl										       foreach(n)


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