Subcommand of array, returns the number of keys in the array given by name. Example:
% array set arr {foo 1 bar 2 grill 3}
% array size arr
3It has been pointed out in the Tcl chatroom that array size is almost double as slow as array statistics which returns much more data (try it to see..) If the speed matters, replace calls to array size with
lindex [array statistics arrname] 0