PHP 教程
PHP array_slice() 函數(shù)
實(shí)例
從數(shù)組的第二個(gè)元素開(kāi)始取出，并返回直到數(shù)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(yùn)行代碼 ?
定義和用法
array_slice() 函數(shù)返回?cái)?shù)組中的選定部分。
注釋：如果數(shù)組有字符串鍵名，所返回的數(shù)組將保留鍵名（參見(jiàn)實(shí)例 4）。
語(yǔ)法
array_slice(array,start,length,preserve)
| 參數(shù) | 描述 |
|---|---|
| array | 必需。規(guī)定數(shù)組。 |
| start | 必需。數(shù)值。規(guī)定取出元素的開(kāi)始位置。
0 = 第一個(gè)元素。
如果該值設(shè)置為正數(shù)，則從前往后開(kāi)始取。如果該值設(shè)置為負(fù)數(shù)，則從后向前取 start 絕對(duì)值。
-2 意味著從數(shù)組的倒數(shù)第二個(gè)元素開(kāi)始。 |
| length | 可選。數(shù)值。規(guī)定被返回?cái)?shù)組的長(zhǎng)度。
如果該值設(shè)置為整數(shù)，則返回該數(shù)量的元素。如果該值設(shè)置為負(fù)數(shù)，則函數(shù)將在舉例數(shù)組末端這么遠(yuǎn)的地方終止取出。如果該值未設(shè)置，則返回從 start 參數(shù)設(shè)置的位置開(kāi)始直到數(shù)組末端的所有元素。
|
| preserve | 可選。規(guī)定函數(shù)是保留鍵名還是重置鍵名。可能的值：
|
技術(shù)細(xì)節(jié)
| 返回值： | 返回?cái)?shù)組中的選定部分。 |
|---|---|
| PHP 版本： | 4+ |
| 更新日志： | preserve 參數(shù)是在 PHP 5.0.2 中新增的。 |
更多實(shí)例
實(shí)例 1
從數(shù)組的第一個(gè)元素開(kāi)始取出，并返回兩個(gè)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(yùn)行代碼 ?
實(shí)例 2
使用負(fù)的 start 參數(shù)：
<?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));
?>
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實(shí)例 3
帶有設(shè)置為 true 的 preserve 參數(shù)：
<?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));
?>
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實(shí)例 4
帶有字符串和整數(shù)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));
?>
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完整的 PHP Array 參考手冊(cè)其他擴(kuò)展