(PHP 4, PHP 5)
array_slice — 从数组中取出一段
$array
, int $offset
[, int $length
[, bool $preserve_keys
]] )
array_slice() 返回根据 offset 和
length 参数所指定的 array
数组中的一段序列。
如果 offset 非负，则序列将从 array
中的此偏移量开始。如果 offset 为负，则序列将从
array 中距离末端这么远的地方开始。
如果给出了 length 并且为正，则序列中将具有这么多的单元。如果给出了
length 并且为负，则序列将终止在距离数组末端这么远的地方。如果省略，则序列将从
offset 开始一直到 array 的末端。
注意 array_slice() 默认将重置数组的键。自
PHP 5.0.2 起，可以通过将
preserve_keys 设为 TRUE 来改变此行为。
Example #1 array_slice() 例子
<?php
$input = array("a", "b", "c", "d", "e");
$output = array_slice($input, 2); // returns "c", "d", and "e"
$output = array_slice($input, -2, 1); // returns "d"
$output = array_slice($input, 0, 3); // returns "a", "b", and "c"
// note the differences in the array keys
print_r(array_slice($input, 2, -1));
print_r(array_slice($input, 2, -1, true));
?>
以上例程会输出：
Array
(
[0] => c
[1] => d
)
Array
(
[2] => c
[3] => d
)
参见 array_splice() 和 unset()。
array
The input array.
offset
If offset is non-negative, the sequence will
start at that offset in the array. If
offset is negative, the sequence will
start that far from the end of the array.
length
If length is given and is positive, then
the sequence will have up to that many elements in it. If the array
is shorter than the length, then only the
available array elements will be present. If
length is given and is negative then the
sequence will stop that many elements from the end of the
array. If it is omitted, then the sequence will have everything
from offset up until the end of the
array.
preserve_keys
Note that array_slice() will reorder and reset the
numeric array indices by default. You can change this behaviour by setting
preserve_keys to TRUE.
Returns the slice.
| 版本 | 说明 |
|---|---|
| 5.0.2 |
The optional preserve_keys parameter was added.
|
Example #2 array_slice() examples
<?php
$input = array("a", "b", "c", "d", "e");
$output = array_slice($input, 2); // returns "c", "d", and "e"
$output = array_slice($input, -2, 1); // returns "d"
$output = array_slice($input, 0, 3); // returns "a", "b", and "c"
// note the differences in the array keys
print_r(array_slice($input, 2, -1));
print_r(array_slice($input, 2, -1, true));
?>
以上例程会输出：
Array
(
[0] => c
[1] => d
)
Array
(
[2] => c
[3] => d
)