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array(n) - array, array - Manipulate array variables - man n array

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



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(3,n) there are any more elements left to be processed in(1,8)
              an array search, 0 if(3,n) 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(3,n) an array has
              an element with an empty name, since the return value from array
              nextelement  won't  indicate  whether  the  search has been com-
              pleted.

       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(3,n) arrayName is an array variable, 0 if(3,n)  there  is  no
              variable by that name or if(3,n) it is a scalar variable.

       array get arrayName ?pattern?
              Returns  a list containing pairs of elements.  The first element
              in(1,8) each pair is the name of an element in(1,8) arrayName and the sec-
              ond 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(1,8) the
              result.  If pattern is specified, then only those elements whose
              names  match  pattern (using the matching rules of string(3,n) match)
              are included.  If arrayName isn't the name of an array variable,
              or  if(3,n)  the  array  contains  no elements, then an empty list is
              returned.

       array names arrayName ?mode? ?pattern?
              Returns a list containing the names of all of  the  elements  in(1,8)
              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(1,8) the
              array.  If not specified, mode defaults to -glob.  See the docu-
              mentation  for string(3,n) match for information on glob(1,3,7,n) style match-
              ing, and the documentation for regexp(3,n) for information on  regexp(3,n)
              matching.  If pattern is omitted then the command returns all of
              the element names in(1,8) the array.  If there are no (matching) ele-
              ments  in(1,8)  the array, or if(3,n) arrayName isn't the name of an array
              variable, then an empty string(3,n) is returned.

       array nextelement arrayName searchId
              Returns the name of the next element in(1,8) arrayName, or  an  empty
              string(3,n)  if(3,n)  all elements of arrayName have already been returned
              in(1,8) this search.  The searchId argument  identifies  the  search,
              and must have been the return value of an array startsearch com-
              mand.  Warning:  if(3,n) elements are added to or  deleted  from  the
              array, then all searches are automatically terminated just as if(3,n)
              array donesearch had been invoked; this will  cause  array  nex-
              telement operations to fail for those searches.

       array set(7,n,1 builtins) arrayName list
              Sets the values of one or more elements in(1,8) arrayName.  list must
              have a form like that returned by array get,  consisting  of  an
              even  number  of elements.  Each odd-numbered element in(1,8) list is
              treated as an element name within arrayName, and  the  following
              element  in(1,8)  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(3,n) giving the number of elements in(1,8) the
              array.  If arrayName isn't 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 ele-
              ments in(1,8) 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(1,8) 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(1,8) the table, the number of buckets, and
              the utilization of the buckets.

       array unset arrayName ?pattern?
              Unsets all of the elements  in(1,8)  the  array  that  match  pattern
              (using  the matching rules of string(3,n) match).  If arrayName isn't
              the name of an array variable or there are no matching  elements
              in(1,8)  the  array,  no error(8,n) 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(7,n,1 builtins) colorcount {
           red   1
           green 5
           blue  4
           white 9 }

       foreach {color count} [array get colorcount] {
           puts(3,n) "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(3,n) "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(3,n) "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(1,8) 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(3,n)(n), variable(n), trace(3x,n,3x _nc_tracebits)(n), foreach(n)


KEYWORDS
       array, element names, search



Tcl                                   8.3                             array(n)

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