PHP Data structure queue (SplQueue) and priority queue (SplPriorityQueue) simple use of instances, priority queue data structure _ PHP Tutorial

The PHP Data structure queue (SplQueue) and the priority queue (SplPriorityQueue) are simple to use instances, and the priority queue data structure. PHP Data structure queue (SplQueue) and priority queue (SplPriorityQueue) are simple to use instances. The data structure of priority queue data structure queue is simpler, just like queuing in our daily life, PHP Data structure queue (SplQueue) and priority queue (SplPriorityQueue) simple use of instances, priority queue data structure

The data structure of queue is simpler, just like queuing in our daily life. it features FIFO ).

In php spl, the SplQueue class implements queue operations. like the stack, it can also inherit the double-stranded table (spldoubly1_list) for easy implementation.
The summary of the SplQueue class is as follows:

SplQueue is easy to use as follows:

The code is as follows:
$ Queue = new SplQueue ();

/**
* The difference between a queue and a double-stranded table is that the IteratorMode is changed. the stack IteratorMode can only be:
* (1) spldoubly1_list: IT_MODE_FIFO | spldoubly1_list: IT_MODE_KEEP (default value: Save data after iteration)
* (2) spldoubly1_list: IT_MODE_FIFO | spldoubly1_list: IT_MODE_DELETE (delete data after iteration)
*/
$ Queue-> setIteratorMode (spldoubly1_list: IT_MODE_FIFO | spldoubly1_list: IT_MODE_DELETE );

// SplQueue: enqueue () is actually the spldoubly1_list: push ()
$ Queue-> enqueue ('A ');
$ Queue-> enqueue ('B ');
$ Queue-> enqueue ('C ');

// SplQueue: dequeue () is actually the spldoubly1_list: shift ()
Print_r ($ queue-> dequeue ());

Foreach ($ queue as $ item ){
Echo $ item. PHP_EOL;
}

Print_r ($ queue );

The priority queue SplPriorityQueue is implemented based on the heap (introduced later.
The Class Summary of SplPriorityQueue is as follows:

Simple use of SplPriorityQueue:

$ Pq = new SplPriorityQueue (); $ pq-> insert ('A', 10); $ pq-> insert ('B', 1 ); $ pq-> insert ('C', 8); echo $ pq-> count (). PHP_EOL; // 3 echo $ pq-> current (). PHP_EOL; // a/*** sets the element queuing mode * SplPriorityQueue: EXTR_DATA only extracts the value * SplPriorityQueue: EXTR_PRIORITY only extracts the priority * SplPriorityQueue :: EXTR_BOTH extract array containing value and priority */$ pq-> setExtractFlags (SplPriorityQueue: EXTR_DATA); while ($ pq-> valid ()) {print_r ($ pq-> current (); // a c B $ pq-> next ();}

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