The SplPriorityQueue::key() function is an inbuilt function in PHP that is used to return the current node index.
Syntax:
mixed SplPriorityQueue::key()
Parameters: This function does not accept any parameter.
Return Value: This function returns the current node index.
Example:
PHP
<?php // Declare a class class priorityQueue extends SplPriorityQueue {
// Compare function to compare priority
// queue elements
public function compare( $p1 , $p2 ) {
if ( $p1 === $p2 ) return 0;
return $p1 < $p2 ? -1 : 1;
}
} // Create an object of priority queue $obj = new priorityQueue();
// Insert elements into the queue $obj ->insert( "Geeks" ,2);
$obj ->insert( "GFG" ,1);
$obj ->insert( "G4G" ,3);
$obj ->insert( 'G' ,4);
// Use key() function to get the // current key of priority queue var_dump( $obj ->key());
?> |
Output
int(3)
Reference: https://www.php.net/manual/en/splpriorityqueue.key.php