如何在每三个分号(;)之后的位置分解字符串?
示例数据:
$string = 'piece1;piece2;piece3;piece4;piece5;piece6;piece7;piece8;';
所需输出:
$output[0] = 'piece1;piece2:piece3;'
$output[1] = 'piece4;piece5;piece6;'
$output[2] = 'piece7;piece8;'
请注意,保留尾随分号。
我相信你可以用正则表达式做一些巧妙的事情,但为什么不直接分解每个半色,然后一次添加三个。
$tmp = explode(";", $string);
$i=0;
$j=0;
foreach($tmp as $piece) {
if(! ($i++ %3)) $j++; //increment every 3
$result[$j] .= $piece;
}
我能想到的最简单的解决方案是:
$chunks = array_chunk(explode(';', $input), 3);
$output = array_map(create_function('$a', 'return implode(";",$a);'), $chunks);
与其他解决方案基本相同,
explode
并再次加入...
$tmp = explode(";", $string);
while ($tmp) {
$output[] = implode(';', array_splice($tmp, 0, 3));
};
$string = "piece1;piece2;piece3;piece4;piece5;piece6;piece7;piece8;piece9;";
preg_match_all('/([A-Za-z0-9\.]*;[A-Za-z0-9\.]*;[A-Za-z0-9\.]*;)/',$string,$matches);
print_r($matches);
Array
(
[0] => Array
(
[0] => piece1;piece2;piece3;
[1] => piece4;piece5;piece6;
[2] => piece7;piece8;piece9;
)
[1] => Array
(
[0] => piece1;piece2;piece3;
[1] => piece4;piece5;piece6;
[2] => piece7;piece8;piece9;
)
)
也许从不同的角度来看待它。将其全部分解,然后将其重新组合成三元组。就像这样...
$str = "1;2;3;4;5;6;7;8;9";
$boobies = explode(";", $array);
while (!empty($boobies))
{
$foo = array();
$foo[] = array_shift($boobies);
$foo[] = array_shift($boobies);
$foo[] = array_shift($boobies);
$bar[] = implode(";", $foo) . ";";
}
print_r($bar);
数组 ( [0] => 1;2;3; [1] => 4;5;6; [2] => 7;8;9; )
这是一个正则表达式方法,我不能说它太好看了。
$str='';
for ($i=1; $i<20; $i++) {
$str .= "$i;";
}
$split = preg_split('/((?:[^;]*;){3})/', $str, -1,
PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
输出:
Array
(
[0] => 1;2;3;
[1] => 4;5;6;
[2] => 7;8;9;
[3] => 10;11;12;
[4] => 13;14;15;
[5] => 16;17;18;
[6] => 19;
)
另一种正则表达式方法。
<?php
$string = 'piece1;piece2;piece3;piece4;piece5;piece6;piece7;piece8';
preg_match_all('/([^;]+;?){1,3}/', $string, $m, PREG_SET_ORDER);
print_r($m);
结果:
Array
(
[0] => Array
(
[0] => piece1;piece2;piece3;
[1] => piece3;
)
[1] => Array
(
[0] => piece4;piece5;piece6;
[1] => piece6;
)
[2] => Array
(
[0] => piece7;piece8
[1] => piece8
)
)
正则表达式分割
$test = ";2;3;4;5;6;7;8;9;10;;12;;14;15;16;17;18;19;20";
// match all groups that:
// (?<=^|;) follow the beginning of the string or a ;
// [^;]* have zero or more non ; characters
// ;? maybe a semi-colon (so we catch a single group)
// [^;]*;? again (catch second item)
// [^;]* without the trailing ; (to not capture the final ;)
preg_match_all("/(?<=^|;)[^;]*;?[^;]*;?[^;]*/", $test, $matches);
var_dump($matches[0]);
array(7) {
[0]=>
string(4) ";2;3"
[1]=>
string(5) "4;5;6"
[2]=>
string(5) "7;8;9"
[3]=>
string(6) "10;;12"
[4]=>
string(6) ";14;15"
[5]=>
string(8) "16;17;18"
[6]=>
string(5) "19;20"
}
<?php
$str = 'piece1;piece2;piece3;piece4;piece5;piece6;piece7;piece8;';
$arr = array_map(function ($arr) {
return implode(";", $arr);
}, array_chunk(explode(";", $str), 3));
var_dump($arr);
输出
array(3) {
[0]=>
string(20) "piece1;piece2;piece3"
[1]=>
string(20) "piece4;piece5;piece6"
[2]=>
string(14) "piece7;piece8;"
}
与@Sebastian 之前的回答类似,我推荐使用重复模式的
preg_split()
。不同之处在于,通过使用非捕获组并附加 \K
来重新启动全字符串匹配,您可以省去编写 PREG_SPLIT_DELIM_CAPTURE
标志。
代码:(演示)
$string = 'piece1;piece2;piece3;piece4;piece5;piece6;piece7;piece8;';
var_export(preg_split('/(?:[^;]*;){3}\K/', $string, 0, PREG_SPLIT_NO_EMPTY));
可以在这里找到每 2 个事物之后进行分割的类似技术。该片段实际上在最后一个空格字符之前写入
\K
,以便在分割时消耗尾部空格。