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php数组函数序列之array_slice()

Mar 18, 2017 pm 04:10 PM
array_slicephp array

array_slice()定义和用法

注释:如果数组有字符串键,所返回的数组将保留键名。(参见例子 4)
语法
array_slice(array,offset,length,preserve)参数 描述
array 必需。规定输入的数组。
offset 必需。数值。规定取出元素的开始位置。
如果是正数,则从前往后开始取,如果是负值,从后向前取 offset 绝对值。
length 可选。数值。规定被返回数组的长度。
如果是负数,则从后向前,选取该值绝对值数目的元素。如果未设置该值,则返回所有元素。
preserve 可选。可能的值:
true - 保留键
false - 默认 - 重置键
例子 1

代码如下:

<?php 
$a=array(0=>"Dog",1=>"Cat",2=>"Horse",3=>"Bird"); 
print_r(array_slice($a,1,2)); 
?>

输出:

Array ( [0] => Cat [1] => Horse )

例子 2
带有负的 offset 参数: 

代码如下:

<?php 
$a=array(0=>"Dog",1=>"Cat",2=>"Horse",3=>"Bird"); 
print_r(array_slice($a,-2,1)); 
?>

输出:

Array ( [0] => Horse )

例子 3
preserve 参数设置为 true:

代码如下:

<?php 
$a=array(0=>"Dog",1=>"Cat",2=>"Horse",3=>"Bird"); 
print_r(array_slice($a,1,2,true)); 
?>

输出:

Array ( [1] => Cat [2] => Horse )

例子 4
带有字符串键:

代码如下:

<?php 
$a=array("a"=>"Dog","b"=>"Cat","c"=>"Horse","d"=>"Bird"); 
print_r(array_slice($a,1,2)); 
?>

输出:

Array ( [b] => Cat [c] => Horse )

以上就是php数组函数序列之array_slice() - 在数组中根据条件取出一段值,并返回_php技巧的内容,更多相关内容请关注PHP中文网(www.php.cn)!

相关文章:

php array_slice函数的使用以及参数详解

php array_slice 取出数组中的一段序列实例

php中array_slice和array_splice函数解析

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