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 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 won't 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
isn't the name of an array variable, or if 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 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 speci-fied, specified,
fied, 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 pat-tern pattern
tern 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 isn't 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 termi-nated terminated
nated just as if array donesearch had been invoked; this will cause array nextelement opera-tions operations
tions 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 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
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 nex-telement nextelement
telement and array donesearch commands; it allows multiple searches to be underway simultane-ously simultaneously
ously 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 array- |
Name | |
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 ?pat- |
tern? | |
Unsets all of the elements in the array that match pattern (using the matching rules of string |
match). If arrayName isn't 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)
|