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

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NAME

       array - Manipulate array variables

SYNOPSIS

       array option arrayName ?arg arg ...?
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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 pat-
	      tern (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 done-
	      search 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 nex-
	      telement command will return the names of the individual elements in the array.  When the search has been completed, the array done-
	      search  command  should  be invoked.  The return value is a search identifier that must be used in array nextelement and array done-
	      search 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 exam-
	      ples 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(n), string(n), variable(n), trace(n), foreach(n)

KEYWORDS

       array, element names, search

Tcl									8.3								  array(n)