Stack example
` Demonstration of the stack commands
`
` ADD TO stack - Adds a new item to the end of the array and
` sets the current index to point to that item.
` REMOVE FROM stack - Removes the first item at the front of the
` array sets the current index to point to the
` new front item.
` I use ArrayName() to access the current item (eg to set the values
` in the item just added to the stack, and to
` read the value at the top of the stack).
` Several things to note here:
` Adding to the stack automatically increases the size of the array.
` Removing from the stack automatically decreases the size of the
` array.
` You cannot create an empty array (at the moment - Lee may include
` it in Update 6) so the array needs to be cleared before you use
` it.
` No example of the 'array index to stack', because the current item
` is always pointing to the top of the stack either when adding
` or removing. This command may be required when switching between
` using and array/queue/list as a stack.
dim a() as integer
empty array a()
print "Add 5 items to the stack"
for i=1 to 5
n = rnd(1000)
print " Adding "; n; " to the stack"
add to stack a()
a() = n
next i
print
PrintStack()
print
print "Pop 2 items from the stack"
for i=1 to 2
print " Removing "; a(); " from the stack"
remove from stack a()
next i
print
PrintStack()
print
print "Add 5 more entries to the stack"
for i=0 to 4
n = rnd(1000)
print " Adding "; n; " to the stack"
add to stack a()
a() = n
next i
print
PrintStack()
print
print "Now remove items until the stack is empty"
while array index valid( a() )
print " Removing "; a(); " from the stack"
remove from stack a()
endwhile
print
PrintStack()
wait key
end
function PrintStack()
if array count( a() ) >= 0
print "The stack has "; array count( a() )+1; " items"
for i=0 to array count( a() )
print " Item "; i; " = "; a(i)
next i
else
print "The stack is empty"
endif
endfunction
Queue example:
` Demonstration of the queue commands
`
` ADD TO QUEUE - Adds a new item to the end of the array and
` sets the current index to point to that item.
` REMOVE FROM QUEUE - Removes the first item at the front of the
` array sets the current index to point to the
` new front item.
` I use ArrayName() to access the current item (eg to set the values
` in the item just added to the queue).
` I use ArrayName(0) to access the front of the queue (eg to read the
` values prior to removing from the queue)
` - see below for the reason.
` Several things to note here:
` Adding to the queue automatically increases the size of the array.
` Removing from the queue automatically decreases the size of the
` array.
` You cannot create an empty array (at the moment - Lee may include
` it in Update 6) so the array needs to be cleared before you use
` it.
` No example of the 'array index to queue', because there is simply
` no need for this command (in my opinion).
` All it does is set the current index to the first item of the
` array, and you can get that value yourself by accessing array(0).
` Adding a new item to the queue resets the index to the last item
` in the array, and continually switching back to get the next
` value at the front of the queue is a pain.
dim a() as integer
empty array a()
print "Add 5 items to the queue"
for i=1 to 5
n = rnd(1000)
print " Adding "; n; " to the queue"
add to queue a()
a() = n
next i
print
PrintQueue()
print
print "Pop 2 items from the queue"
for i=1 to 2
print " Removing "; a(0); " from the queue"
remove from queue a()
next i
print
PrintQueue()
print
print "Add 5 more entries to the queue"
for i=0 to 4
n = rnd(1000)
print " Adding "; n; " to the queue"
add to queue a()
a() = n
next i
print
PrintQueue()
print
print "Now remove items until the queue is empty"
while array index valid( a() )
print " Removing "; a(0); " from the queue"
remove from queue a()
endwhile
print
PrintQueue()
wait key
end
function PrintQueue()
if array count( a() ) >= 0
print "The queue has "; array count( a() )+1; " items"
for i=0 to array count( a() )
print " Item "; i; " = "; a(i)
next i
else
print "The queue is empty"
endif
endfunction