aspnet外文翻譯-jsp程序-資料下載頁
2025-05-12 19:32本頁面
【導(dǎo)讀】大多數(shù)現(xiàn)代編程語言提供支持某種類型的對象,可以容納一個可變數(shù)目的元素。集合,他們可以輕易地添加和刪除元素,而不必擔(dān)心適當?shù)膬?nèi)存分配。如果你使用經(jīng)典ASP編程。之前,你就可能已經(jīng)熟悉了腳本，字典對象,采集對象的每個元素包含一個參考文本的關(guān)鍵。種方式存儲對象的集合被稱為一個哈希表。有許多類型的集合，除了哈希表。每一種類型的集合是相似的目的:它作為一種手段來存儲不同。一的方法儲存、檢索并借鑒它的各種因素，而.NET框架提供了很多的集合類型為開發(fā)人員使用。事實上,整個的命名空間系統(tǒng)集合是專門從事集合類型和輔助課程。因為在.NET中所有的原始數(shù)據(jù)類型的字符串，整。在本節(jié)中，我們將研究5個集合的.NET框架為開發(fā)人員提供數(shù)組列表，哈希表，可排序列表，的集合類型”的共同特點就是來考察所發(fā)現(xiàn)的集合類型。素由一個字母數(shù)字鍵組成作為哈希表的索引。適用于數(shù)組列表的每個元素的順序，根據(jù)其數(shù)值指標;哈希表的實行隨機
【正文】 ammatically read, write, or remove any element in the collection, regardless of its position. However, the Queue and Stack classes (the remaining two collections we’ll examine) are unique in that they provide sequential access only. Specifically, the Queue class can only access and remove elements in the order they were inserted. 9 Adding, Removing, and Accessing Elements in a Queue Queues are often referred to as First In, First Out (FIFO) data structures because the Nth element inserted will be the Nth element removed or accessed. It helps to think of the queue data structure as a line of people. There are two parts to a queue as there are two parts to any line up: the tail of the queue, where people new to the line start waiting, and the head of the queue, where the next person in line waits to be served. In a line, the person who is standing in line first will be first served。 the person standing second will be served second, and so on。 in a queue, the element that is added first will be the element that is removed or accessed first, whereas the second element added will be the second element removed or accessed. The .NET Framework provides support for the queue data structure with the Queue class. To add an element to the tail, use the Enqueue method. To retrieve and remove an element from the head of a queue, use Dequeue. As with the other collection types we’ve examined thus far, the Queue class contains a Clear method to remove all elements. To simply examine the element at the head without altering the queue, use the Peek method. As with all the other collections, the elements of a Queue can be iterated through using an enumerator or a For Each Next loop. Working with the Stack Class A stack is a data structure similar to a queue in that is supports only sequential , a stack does bear one major difference from a queue: rather than storing elements with a First In, First Out (FIFO) semantic, a stack uses Last In, First Out (LIFO). A crowded elevator behaves similar to a stack: the first person who enters the crowded elevator is the last person to leave, whereas the last person to board the elevator is the first out when it reaches its destination. Adding, Removing, and Accessing Elements in a Stack The .NET Framework provides an implementation of the stack data type with the Stack class. A stack has two basic operations: adding an element to the top of the stack, which is acplished with the Push method, and removing an element from the top of the stack, acplished via the Pop method. Similar to the Queue class, the Stack class also contains a Peek method to permit developers to access the top of the stack without removing the element. Similarities Among the Collection Types Because each collection has the same basic functionality—to serve as a variablesized storage medium for Objects—it is not surprising that the collection types have much in mon with one another. All have methods to add and remove elements from the collection. The Count property, which returns the total number of elements in the collection, is mon among all collection types. Conclusion The .NET Framework provides developers with a number of powerful collectiontype classes, greatly extending the functionality of the object, the sole collection type available for classic ASP developers. These collections, although each have unique capabilities, are more alike than they are different. All of them share similar methods and properties, and can all have their elements iterated through using a number of techniques.
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