'''`[array] size`''' ''`arrayName`''



** Synopsis **


'''`[array] size`''' ''`arrayName`''



** Description **

Returns the number of variables in the array. If ''`arrayName`'' isn't the name
of an array then '''`0`''' is returned.

Example:

======none
% array set arr {foo 1 bar 2 grill 3}
% array size arr
3
====== 

It has been pointed out in the [Tcl chatroom] that '''array size''' is almost twice as slow as '''`[array statistics]`''' which returns much more data. If the speed matters, replace '''`array size arrayName`''' with '''`[[lindex [[array statistics arrayName]] 0]]`'''

[DKF]: However, please note that `[array statistics]` is not guaranteed to return the right answer.  See this (trimmed) transcript for why:

======none
% array set foo {a a b b c c d d e e}
% array stat foo
5 entries in table, 4 buckets
[...]
average search distance for entry: 1.2
% # Demonstrate the case that everyone thinks of first...
% unset foo(b)
% array stat foo
4 entries in table, 4 buckets
[...]
average search distance for entry: 1.3
% set foo(b) b
b
% array stat foo
5 entries in table, 4 buckets
[...]
average search distance for entry: 1.2
% # Now demonstrate the nasty case which makes things fall apart...
% upvar 0 foo(b) b
% unset b
% array stat foo
5 entries in table, 4 buckets
[...]
average search distance for entry: 1.2
% array size foo
4
====== 

----

''[MGS]'' 2003-09-24: With 8.4.4, I find '''`[array] size arrayName`''' to be the quickest, with '''`[llength] [[[array] names arrayName]]`''' about two to three times as slow, and '''`[lindex] [[[array] statistics arrayName]] 0`''' about ten times as slow.


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