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A List as a Stack

Until now lists (and arrays) have been presented as linear arrays of data with indexes identifying each element:

Use your imagination for a moment and imagine the array elements as a vertical stack:

In computer terminology, this list is called a stack. Stacks are useful for accumulating tasks that you want processed in order. A good example is a game of Klondike Solitaire. Each of the seven piles of cards represents a stack. Initially, cards are placed onto the stack face down. As they are needed, they are turned over and ...