Ds \ Deque :: copy()function是PHP中的内置函数, 用于返回Deque的副本。这将返回Deque的浅表副本。
语法如下:
public Ds\Deque::copy ( void ) : Ds\Deque
参数:此函数不包含任何参数。
返回值:此函数返回Deque元素的副本。
下面的程序说明了Ds \ Deque :: copy()PHP中的功能:
程序1:
<?php
// Declare deque
$deck = new \Ds\Deque([1, 2, 3, 4, 5, 6]);
echo ( "Elements in the Deque\n" );
// Display the Deque elements
var_dump( $deck );
// Use copy() function to
// copy the Deque
$deck_copy = $deck -> copy ();
echo ( "\nCopy Deque elements\n" );
// Display the Deque elements
var_dump( $deck_copy );
?>
输出如下:
Elements in the Deque
object(Ds\Deque)#1 (6) {
[0]=>
int(1)
[1]=>
int(2)
[2]=>
int(3)
[3]=>
int(4)
[4]=>
int(5)
[5]=>
int(6)
}
Copy Deque elements
object(Ds\Deque)#2 (6) {
[0]=>
int(1)
[1]=>
int(2)
[2]=>
int(3)
[3]=>
int(4)
[4]=>
int(5)
[5]=>
int(6)
}
程式2:
<?php
// Declare deque
$deck = new \Ds\Deque([ "geeks" , "for" , "geeks" ]);
echo ( "Elements in the Deque\n" );
// Display the Deque elements
print_r( $deck );
// Use copy() function to
// copy the Deque
$deck_copy = $deck -> copy ();
echo ( "\nCopy Deque elements\n" );
// Display the Deque elements
print_r( $deck_copy );
?>
输出如下:
Elements in the Deque
Ds\Deque Object
(
[0] => geeks
[1] => for
[2] => geeks
)
Copy Deque elements
Ds\Deque Object
(
[0] => geeks
[1] => for
[2] => geeks
)
参考: http://php.net/manual/en/ds-deque.copy.php