DOKK / manpages / debian 12 / tcl8.6-doc / array.3tcl.en
array(3tcl) Tcl Built-In Commands array(3tcl) 







array - Manipulate array variables








array option arrayName ?arg arg ...?










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:



  

  
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.

  

  
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.

  

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

  

  
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.

  

  
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.

  

  
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.

  

  
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.

  

  
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.

  

  
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.

  

  
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.

  

  
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.












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










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








array, element names, search







  

    8.3
    Tcl