PHP array_slice() 函數
實例
從數組的第二個元素開始取出,並返回直到數組末端的所有元素:
<?php
$a=array("red","green","blue","yellow","brown");
print_r(array_slice($a,2));
?>
$a=array("red","green","blue","yellow","brown");
print_r(array_slice($a,2));
?>
運行實例»
定義和用法
array_slice() 函數返回數組中的選定部分。
註釋:如果數組有字符串鍵名,所返回的數組將保留鍵名(參見實例4)。
語法
array_slice( array,start,length,preserve )
参数 | 描述 |
---|---|
array | 必需。规定数组。 |
start | 必需。数值。规定取出元素的开始位置。
0 = 第一个元素。
如果该值设置为正数,则从前往后开始取。如果该值设置为负数,则从后向前取 start 绝对值。
-2 意味着从数组的倒数第二个元素开始。 |
length | 可选。数值。规定被返回数组的长度。
如果该值设置为整数,则返回该数量的元素。如果该值设置为负数,则函数将在举例数组末端这么远的地方终止取出。如果该值未设置,则返回从 start 参数设置的位置开始直到数组末端的所有元素。
|
preserve | 可选。规定函数是保留键名还是重置键名。可能的值:
|
技術細節
返回值: | 返回數組中的選定部分。 |
---|---|
PHP 版本: | 4+ |
更新日誌: | preserve參數是在PHP 5.0.2中新增的。 |
更多實例
實例1
從數組的第一個元素開始取出,並返回兩個元素:
<?php
$a=array("red","green","blue","yellow","brown");
print_r(array_slice($a,1,2));
?>
$a=array("red","green","blue","yellow","brown");
print_r(array_slice($a,1,2));
?>
運行實例»
實例2
使用負的start 參數:
<?php
$a=array("red","green","blue","yellow","brown");
print_r(array_slice($a,-2,1));
?>
$a=array("red","green","blue","yellow","brown");
print_r(array_slice($a,-2,1));
?>
運行實例»
實例3
帶有設置為true 的preserve 參數:
<?php
$a=array("red","green","blue","yellow","brown");
print_r(array_slice($a,1,2,true));
?>
$a=array("red","green","blue","yellow","brown");
print_r(array_slice($a,1,2,true));
?>
運行實例»
實例4
帶有字符串和整數鍵名:
<?php
$a=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow","e"=>"brown");
print_r(array_slice($a,1,2));
$a=array("0"=>"red","1"=>"green","2"=>"blue","3"=>"yellow","4"=>"brown");
print_r(array_slice($a,1,2));
?>
$a=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow","e"=>"brown");
print_r(array_slice($a,1,2));
$a=array("0"=>"red","1"=>"green","2"=>"blue","3"=>"yellow","4"=>"brown");
print_r(array_slice($a,1,2));
?>
運行實例»
完整的PHP Array參考手冊