array(3tcl)


NAME

   array - Manipulate array variables

SYNOPSIS

   array option arrayName ?arg arg ...?
______________________________________________________________________________

DESCRIPTION

   This  command  performs one of several operations on the variable given
   by arrayName.   Unless  otherwise  specified  for  individual  commands
   below,  arrayName  must be the name of an existing array variable.  The
   option argument determines what action is carried out by  the  command.
   The legal options (which may be abbreviated) are:

   array anymore arrayName searchId
          Returns 1 if there are any more elements left to be processed in
          an array search, 0 if all elements have already  been  returned.
          SearchId  indicates which search on arrayName to check, and must
          have been the return value from a previous invocation  of  array
          startsearch.  This option is particularly useful if an array has
          an element with an empty name, since the return value from array
          nextelement  will  not  indicate  whether  the  search  has been
          completed.

   array donesearch arrayName searchId
          This command terminates an array search  and  destroys  all  the
          state  associated  with  that  search.  SearchId indicates which
          search on arrayName to destroy, and must have  been  the  return
          value  from a previous invocation of array startsearch.  Returns
          an empty string.

   array exists arrayName
          Returns 1 if arrayName is an array variable, 0 if  there  is  no
          variable by that name or if it is a scalar variable.

   array get arrayName ?pattern?
          Returns  a list containing pairs of elements.  The first element
          in each pair is the name of an  element  in  arrayName  and  the
          second  element  of each pair is the value of the array element.
          The order  of  the  pairs  is  undefined.   If  pattern  is  not
          specified, then all of the elements of the array are included in
          the result.  If pattern is specified, then only  those  elements
          whose  names  match  pattern (using the matching rules of string
          match) are included.  If arrayName is not the name of  an  array
          variable,  or  if  the array contains no elements, then an empty
          list is returned.  If traces on the array  modify  the  list  of
          elements, the elements returned are those that exist both before
          and after the call to array get.

   array names arrayName ?mode? ?pattern?
          Returns a list containing the names of all of  the  elements  in
          the array that match pattern.  Mode may be one of -exact, -glob,
          or -regexp.  If specified, mode designates which matching  rules
          to use to match pattern against the names of the elements in the
          array.  If not specified,  mode  defaults  to  -glob.   See  the
          documentation  for  string  match  for information on glob style
          matching, and the documentation for regexp  for  information  on
          regexp matching.  If pattern is omitted then the command returns
          all of the  element  names  in  the  array.   If  there  are  no
          (matching)  elements  in  the  array, or if arrayName is not the
          name of an array variable, then an empty string is returned.

   array nextelement arrayName searchId
          Returns the name of the next element in arrayName, or  an  empty
          string  if  all elements of arrayName have already been returned
          in this search.  The searchId argument  identifies  the  search,
          and  must  have  been  the  return value of an array startsearch
          command.  Warning:  if elements are added to or deleted from the
          array, then all searches are automatically terminated just as if
          array  donesearch  had  been  invoked;  this  will  cause  array
          nextelement operations to fail for those searches.

   array set arrayName list
          Sets the values of one or more elements in arrayName.  list must
          have a form like that returned by array get,  consisting  of  an
          even  number  of elements.  Each odd-numbered element in list is
          treated as an element name within arrayName, and  the  following
          element  in  list is used as a new value for that array element.
          If the variable arrayName does not already  exist  and  list  is
          empty, arrayName is created with an empty array value.

   array size arrayName
          Returns  a  decimal  string giving the number of elements in the
          array.  If arrayName is not the name  of  an  array  then  0  is
          returned.

   array startsearch arrayName
          This  command  initializes  an element-by-element search through
          the array given by arrayName, such that invocations of the array
          nextelement  command  will  return  the  names of the individual
          elements in the array.  When the search has been completed,  the
          array donesearch command should be invoked.  The return value is
          a search identifier that must be used in array  nextelement  and
          array  donesearch  commands;  it  allows multiple searches to be
          underway simultaneously for the same  array.   It  is  currently
          more  efficient  and easier to use either the array get or array
          names, together with foreach, to iterate over all but very large
          arrays.  See the examples below for how to do this.

   array statistics arrayName
          Returns  statistics  about  the  distribution of data within the
          hashtable that represents the array.  This information  includes
          the  number  of entries in the table, the number of buckets, and
          the utilization of the buckets.

   array unset arrayName ?pattern?
          Unsets all of the elements  in  the  array  that  match  pattern
          (using the matching rules of string match).  If arrayName is not
          the name of an array variable or there are no matching  elements
          in  the  array,  no error will be raised.  If pattern is omitted
          and arrayName is an array variable, then the command unsets  the
          entire array.  The command always returns an empty string.

EXAMPLES

          array set colorcount {
             red   1
             green 5
             blue  4
             white 9
          }

          foreach {color count} [array get colorcount] {
             puts "Color: $color Count: $count"
          }
             Color: blue Count: 4
              Color: white Count: 9
              Color: green Count: 5
              Color: red Count: 1

          foreach color [array names colorcount] {
             puts "Color: $color Count: $colorcount($color)"
          }
             Color: blue Count: 4
              Color: white Count: 9
              Color: green Count: 5
              Color: red Count: 1

          foreach color [lsort [array names colorcount]] {
             puts "Color: $color Count: $colorcount($color)"
          }
             Color: blue Count: 4
              Color: green Count: 5
              Color: red Count: 1
              Color: white Count: 9

          array statistics colorcount
             4 entries in table, 4 buckets
              number of buckets with 0 entries: 1
              number of buckets with 1 entries: 2
              number of buckets with 2 entries: 1
              number of buckets with 3 entries: 0
              number of buckets with 4 entries: 0
              number of buckets with 5 entries: 0
              number of buckets with 6 entries: 0
              number of buckets with 7 entries: 0
              number of buckets with 8 entries: 0
              number of buckets with 9 entries: 0
              number of buckets with 10 or more entries: 0
              average search distance for entry: 1.2

SEE ALSO

   list(3tcl), string(3tcl), variable(3tcl), trace(3tcl), foreach(3tcl)

KEYWORDS

   array, element names, search





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