The SplHeap::rewind() function is an inbuilt function in PHP that is used to rewind the iterator to the beginning.
Generally, the Heap Data Structure are of two types:
- Max-Heap: In a Max-Heap the key present at the root node must be greatest among the keys present at all of its children. The same property must be recursively true for all sub-trees in that Binary Tree.
- Min-Heap: In a Min-Heap the key present at the root node must be minimum among the keys present at all of its children. The same property must be recursively true for all sub-trees in that Binary Tree.
Syntax:
void SplHeap::rewind()
Parameters: This function does not accept any parameter.
Return Value: This function does not return any value.
Below programs illustrate the SplHeap::rewind() function in PHP.
Example 1:
PHP
<?php   // Create a new empty Max Heap $heap = new SplMaxHeap();   $heap->insert('System'); $heap->insert('GFG'); $heap->insert('ALGO'); $heap->insert('C'); $heap->insert('Geeks'); $heap->insert('neveropen');   // Use rewind() function $heap->rewind();     // Display the current element var_dump($heap->current());     ?> |
Output:
string(6) "System"
Example 2:
PHP
<?php   // Create a new empty Min Heap $heap = new SplMinHeap();   $heap->insert('System'); $heap->insert('GFG'); $heap->insert('ALGO'); $heap->insert('C'); $heap->insert('Geeks'); $heap->insert('neveropen');   // Use rewind() function $heap->rewind();     // Display the current element var_dump($heap);   ?> |
Output:
object(SplMinHeap)#1 (3) {
["flags":"SplHeap":private]=>
int(0)
["isCorrupted":"SplHeap":private]=>
bool(false)
["heap":"SplHeap":private]=>
array(6) {
[0]=>
string(4) "ALGO"
[1]=>
string(1) "C"
[2]=>
string(3) "GFG"
[3]=>
string(6) "System"
[4]=>
string(5) "Geeks"
[5]=>
string(13) "neveropen"
}
}
