讲解php字符串的有序拆分的相关操作

<!--?php
$str = "Shanghai";
echo chunk_split($str,1,".");
?-->

<!--?php
$str = 'one|two|three|four';
print_r(explode('|', $str));
print_r(explode('|', $str, 2));
// 负数的 limit（自 PHP 5.1 起）
print_r(explode('|', $str, -1));
?-->

Array
(
    [0] => one
    [1] => two
    [2] => three
    [3] => four
)
Array
(
    [0] => one
    [1] => two|three|four
)
Array
(
    [0] => one
    [1] => two
    [2] => three
) 
str_split()
str_split() 将字符串分割为一个数组，成功返回一个数组。
array str_split( string string [, int length] )

<!--?php
$str = 'one two three';
$arr1 = str_split($str);
$arr2 = str_split($str, 3);
print_r($arr1);
print_r($arr2);
?-->

Array
(
    [0] => o
    [1] => n
    [2] => e
    [3] => 
    [4] => t
    [5] => w
    [6] => o
    [7] => 
    [8] => t
    [9] => h
    [10] => r
    [11] => e
    [12] => e
)
Array
(
    [0] => one
    [1] =>  tw
    [2] => o t
    [3] => hre
    [4] => e
)