<?php
$str = "asdf{title}asdf{author}sadf{con}asfasdfasdfasf";
$mode = "/{(.*)}/U";
$flags1 = PREG_PATTERN_ORDER; // 默认选项。整个数组是二维数组，$arr1[0]是包括边界所构成匹配字符串的数组，$arr1[1]除去边界所构成的匹配字符串的数组；
preg_match_all($mode, $str, $arr1, $flags1);
print_r($arr1);
echo "\r\n\r\n";
$flags2 = PREG_SET_ORDER; // 整个数组是二维数组，$arr2[0][0]是第一个包括边界所构成的匹配的字符串，$arr2[0][1]是第一个除去边界所构成的匹配的字符串，之后的数组以此类推
preg_match_all($mode, $str, $arr2, $flags2);
print_r($arr2);
echo "\r\n\r\n";
$flags3 = PREG_OFFSET_CAPTURE; // 整个数组是三维数组，$arr3[0][0][0]是第一个包括边界所构成的匹配的字符串，$arr3[0][0][1]是到达第一个匹配字符串的边界的偏移量（边界不算在内），之后以此类推，$arr2[1][0][0]是第一个包括边界所构成的匹配的字符串，$arr3[1][0][1]是到达第一个匹配字符串的边界的偏移量（边界算在内）;
preg_match_all($mode, $str, $arr3, $flags3);
print_r($arr3);
输出：
PREG_PATTERN_ORDER：
Array
(
[0] => Array
(
[0] => {title}
[1] => {author}
[2] => {con}
)
[1] => Array
(
[0] => title
[1] => author
[2] => con
)
)
PREG_SET_ORDER：
Array
(
[0] => Array
(
[0] => {title}
[1] => title
)
[1] => Array
(
[0] => {author}
[1] => author
)
[2] => Array
(
[0] => {con}
[1] => con
)
)
PREG_OFFSET_CAPTURE：
Array
(
[0] => Array
(
[0] => Array
(
[0] => {title}
[1] => 4
)
[1] => Array
(
[0] => {author}
[1] => 15
)
[2] => Array
(
[0] => {con}
[1] => 27
)
)
[1] => Array
(
[0] => Array
(
[0] => title
[1] => 5
)
[1] => Array
(
[0] => author
[1] => 16
)
[2] => Array
(
[0] => con
[1] => 28
)
)
)
延伸阅读：