programming-for-dummies

364
Using a Stack
To use the Peek command, you have to assign the value of the Peek command
to a variable like this:
Dim BlowMyStack as New Stack
Dim X as Object
BlowMyStack.Push (“My cat”)
BlowMyStack.Push (108.75)
BlowMyStack.Push (“Fat dog”)
X = BlowMyStack.Peek
The preceding code assigns the value “Fat dog” to the X variable, which is
declared as an Object data type. (In Visual Basic.NET, an Object data type
can hold any type of data including integers, strings, and decimal numbers,
such as (47.748).
The Peek command retrieves the data but leaves it on top of the stack.
If you want to remove data, you use the Pop command, which retrieves and
removes data, as shown in the following Visual Basic.NET example:
Dim BlowMyStack as New Stack
Dim X as Object
BlowMyStack.Push (“My cat”)
BlowMyStack.Push (108.75)
BlowMyStack.Push (“Fat dog”)
X = BlowMyStack.Pop
Figure 4-3 shows the difference between the Peek and the Pop commands.
Figure 4-3:
The Peek
command
retrieves
data, but
the Pop
command
retrieves
and removes
data from
the stack.
X = “Fat dog”
Fat dog
108.75
My cat
The “Peek” command
copies data off the
stack but leaves the
data still on the stack.
X = “Fat dog”
108.75
My cat
The “Pop” command
removes data off
the stack.