Introduction and use of PHP double-stranded table

Introduction and use of PHP double-stranded table

This article mainly introduces the introduction of PHP double-stranded table (spldoublyshortlist) and related information on using instances. For more information, see

A double-chain table is an important linear storage structure. For each node in a double-chain table, it not only stores its own information, but also stores the addresses of the front-end and subsequent nodes.

The spldoublyshortlist class in php spl provides operations on double-stranded tables.

The summary of the spldoublyshortlist class is as follows:

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Spldoublyasklist implements Iterator, ArrayAccess, Countable {   Public _ construct (void) Public void add (mixed $ index, mixed $ newval) // The header node of the double-stranded table Public mixed top (void) // Tail node of the double-stranded table Public mixed bottom (void) // Number of double join Table Elements Public int count (void) // Check whether the double-stranded table is empty Public bool isEmpty (void)     // Index of the current node Public mixed key (void) // Move to the previous record Public void prev (void) // Move to the next record Public void next (void) // Current record Public mixed current (void) // Point the pointer to the beginning of the iteration Public void rewind (void) // Check whether there are nodes in the double-stranded table Public bool valid (void)   // Specify whether a node exists at the index Public bool offsetExists (mixed $ index) // Obtain the node value at the specified index Public mixed offsetGet (mixed $ index) // Set the value at the specified index Public void offsetSet (mixed $ index, mixed $ newval) // Delete the node at the specified index Public void offsetUnset (mixed $ index)   // Elements are displayed at the end of the double-stranded table. Public mixed pop (void) // Add elements to the end of the double-stranded table Public void push (mixed $ value)   // Serialized Storage Public string serialize (void) // Deserialization Public void unserialize (string $ serialized)   // Set the iteration Mode Public void setIteratorMode (int $ mode) // Obtain the iterative mode spldoublyshortlist: IT_MODE_LIFO (Stack style) spldoublyshortlist: IT_MODE_FIFO (Queue style) Public int getIteratorMode (void)   // Remove the element from the header of the double-stranded table Public mixed shift (void) // Add an element to the header of the double-stranded table Public void unshift (mixed $ value)   }

Easy to use

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$ List = new spldoublyasklist (); $ List-> push ('A '); $ List-> push ('B '); $ List-> push ('C ');   $ List-> unshift ('top '); $ List-> shift ();   Print_r (array ( 'Pop' => $ list-> pop (), 'Count' => $ list-> count (), 'Isempty' => $ list-> isEmpty (), 'Bottom '=> $ list-> bottom (), 'Top' => $ list-> top () ));   $ List-> setIteratorMode (spldoubly1_list: IT_MODE_FIFO ); Print_r ($ list-> getIteratorMode ());   For ($ list-> rewind (); $ list-> valid (); $ list-> next ()){ Echo $ list-> current (). PHP_EOL; }   Print_r ($ a = $ list-> serialize ()); // Print_r ($ list-> unserialize ($ ));   $ List-> offsetSet (0, 'new one '); $ List-> offsetUnset (0 ); Print_r (array ( 'Offsetexists' => $ list-> offsetExists (4 ), 'Offsetget' => $ list-> offsetGet (0 ),   )); Print_r ($ list );