foreach(1t) [opensolaris man page]

foreach(1T)						       Tcl Built-In Commands						       foreach(1T)

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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 iterations 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 iterations of the loop.

SEE ALSO

       for(1T), while(1T), break(1T), continue(1T)

KEYWORDS

       foreach, iteration, list, looping

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +--------------------+-----------------+
       |  ATTRIBUTE TYPE    | ATTRIBUTE VALUE |
       +--------------------+-----------------+
       |Availability	    | SUNWTcl	      |
       +--------------------+-----------------+
       |Interface Stability | Uncommitted     |
       +--------------------+-----------------+
NOTES

       Source for Tcl is available on http://opensolaris.org.

Tcl																       foreach(1T)

Check Out this Related Man Page

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

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NAME

       for - ``For'' loop

SYNOPSIS

       for start test next body
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DESCRIPTION

       For  is	a  looping command, similar in structure to the C for statement.  The start, next, and body arguments must be Tcl command strings,
       and test is an expression string.  The for command first invokes the Tcl interpreter to execute start.  Then it repeatedly  evaluates  test
       as  an expression; if the result is non-zero it invokes the Tcl interpreter on body, then invokes the Tcl interpreter on next, then repeats
       the loop.  The command terminates when test evaluates to 0.  If a continue command is invoked within body then any  remaining  commands	in
       the  current  execution of body are skipped; processing continues by invoking the Tcl interpreter on next, then evaluating test, and so on.
       If a break command is invoked within body or next, then the for command will return immediately.  The operation of break and  continue  are
       similar to the corresponding statements in C.  For returns an empty string.

       Note:  test  should almost always be enclosed in braces.  If not, variable substitutions will be made before the for command starts execut-
       ing, which means that variable changes made by the loop body will not be considered in the expression.  This is	likely	to  result  in	an
       infinite loop.  If test is enclosed in braces, variable substitutions are delayed until the expression is evaluated (before each loop iter-
       ation), so changes in the variables will be visible.  For an example, try the following script with and without the braces around $x<10:
	      for {set x 0} {$x<10} {incr x} {
		puts "x is $x"
	      }

SEE ALSO

       break, continue, foreach, while

KEYWORDS

       for, iteration, looping

Tcl																	    for(n)

Linux and UNIX Man Pages

foreach(1t) [opensolaris man page]

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