Sometimes, if you have large arrays, it is better to not use foreach and array get to loop through an array, as it creates a list copy of your array with a quite hefty memory cost:
foreach {key value} [array get arrName] {#do something with key and value}Another alternative is
foreach key [array names arrName]] { #get current value with $arrName($key) }
foreach key [lsort -dictionary [array names foo]] { ... }Better do it like this, using while and the array search facilities. (Those are a direct mapping of the C level functionality for a Tcl_HashTable ).
set searchToken [array startsearch largeArray]
while {[array anymore largeArray $searchToken]} {
set key [array nextelement largeArray $searchToken]
set value $largeArray($key)
# do something with key/value
}
array donesearch largeArray $searchTokenQuestion: how big does an array need to be to make this the better approach?