split
(PHP 3, PHP 4, PHP 5)
split — 用正则表达式将字符串分割到数组中
说明
array split ( string pattern, string string [, int limit] )
提示:
preg_split() 函数使用了
Perl 兼容正则表达式语法，通常是比
split() 更快的替代方案。如果不需要正则表达式的威力，则使用
explode() 更快，这样就不会招致正则表达式引擎的浪费。
本函数返回一个字符串数组，每个单元为
string 经区分大小写的正则表达式
pattern 作为边界分割出的子串。如果设定了
limit，则返回的数组最多包含
limit 个单元，而其中最后一个单元包含了
string 中剩余的所有部分。如果出错，则
split() 返回 FALSE。
将 /etc/passwd 中的前四个字段分割出来：
例子 1. split() 例子
如果字符串中有 n 个与
pattern 匹配的项目，则返回的数组将包含
n+1 个单元。例如，如果没有找到
pattern，则会返回一个只有一个单元的数组。当然，如果
string 为空也是这样。
解析可能用斜线，点，或横线分割的日期：
例子 2. split() 例子
// 分隔符可以是斜线，点，或横线
$date = “04/30/1973″;
list($month, $day, $year) = split (‘[/.-]‘, $date);
echo “Month: $month; Day: $day; Year: $year
\n”;
?>
想仿效 Perl 中类似的 @chars =
split(”, $str) 行为，请参考
preg_split() 函数中的例子。
注意 pattern
是一个正则表达式。如果想要用的分割字符是正则表达式中的特殊字符，要先将其转义。如果觉得
split()（或其它任何 regex 函数）行为古怪的话，请阅读包含在
PHP 发行包中 regex/ 子目录下的
regex.7 文件。该文件是手册页面格式，可以用类似
man /usr/local/src/regex/regex.7 的命令来阅读。
参见 preg_split()，spliti()，explode()，implode()，chunk_split()
和 wordwrap()。
add a note
User Contributed Notes
split
dan dot jones at lunarfish dot co dot uk
17-Aug-2006 08:24
Here’s a function to split a string into csv values where they are optionally enclosed by ” to allow values with commas in.
I think it works. Let me know if I’m wrong.
Cheers. Dan
function getCSVValues($string) {
// split the string at double quotes ”
$bits = split(‘”‘,$string);
$elements = array();
for ($i=0;$i
/*
odd numbered elements would have been
enclosed by double quotes
even numbered elements would not have been
*/
if (($i%2) == 1) {
/* if the element number is odd add the
whole string to the output array */
$elements[] = $bits[$i];
} else {
/* otherwise split the unquoted stuff at commas
and add the elements to the array */
$rest = $bits[$i];
$rest = preg_replace(“/^,/”,”",$rest);
$rest = preg_replace(“/,$/”,”",$rest);
$elements = array_merge($elements,split(‘,’,$rest));
}
}
return $elements;
}
destes at ix dot netcom dot com
14-Feb-2006 04:15
Some corrections to robin-at-teddyb’s CSV splitting function. Recall
that the point of this is to properly implement a split() function that
handles data exported to CSV, where data containing commas gets
quote-delimited.
* Problem 1: As jh-at-junetz pointed out, the +1 in robin’s
nonquoted splitting command mistakenly adds an extra element to the
resulting array.
* Problem 2: If consecutive fields are quote-delimited, the
remaining “separator” between them only contains one delimiter and no
actual fields – so an extra element gets added to the parsed array.
* Problem 3: When double-quotes appear in a spreadsheet exported
to CSV, they get escaped by doubling them, i.e. a data field reading
“this is a test of a “special” case” gets written to CSV as, “this is a
test of a “”special”" case”. These quotes are also interpreted as
top-level delimiters and (mistakenly) add extra array elements to the
output.
I have hacked a conversion of “” to a single quote ( ‘ ), but a truly
clever preg_split for the top-level splitter (instead of the explode)
might preserve the original doubled “s without bugging up the top-level
parsing. i.e., a smarter man than I could solve the problem rather
than avoiding it by replacing the bad data.
(current) Solution:
= 1) {
//Break up the string according to the delimiter character
//Each string has extraneous delimiters around it (inc the ones we added
//above), so they need to be stripped off
$temparray = split($splitter, substr($val, $delimlen, strlen($val)-$delimlen-$delimlen ) );
while(list($iarg, $ival) = each($temparray)) {
$result[] = trim($ival);
}
}
// else, the next element needing parsing is a quoted string and the comma
// here is just a single separator and contains no data, so skip it
$instring = 1;
}
}
return $result;
}
?>
RE: gcerretini at technica dot net /UTF8
08-Feb-2006 08:26
Original problem:
=================
I’ve try using split function.
$ferro=”2�12″;
$valore=split(“[�]“,$ferro);
echo $ferro.”
“;
echo “p1-”.$valore[0].”
“;
echo “p2-”.$valore[1].”
“;
echo “p3-”.$valore[2].”
“;
$ferro=”2d12″;
$valore=split(“[d]“,$ferro);
echo $ferro.”
“;
echo “p1-”.$valore[0].”
“;
echo “p2-”.$valore[1].”
“;
echo “p3-”.$valore[2].”
“;
?>
This return:
============
2�12
p1-2
p2-
p3-12
2d12
p1-2
p2-12
p3-
I use charset UTF-8. When I use char � the split function ad an empty string between “2″ and “12″… Why?
Explanation:
============
UTF-8 charset codes some characters (like the “�”
character) into two bytes. In fact the regular expresion
“[�]” contains 4 bytes (4 non-unicode characters). To
demonstrate the real situation I wrote following example:
$ferro=”2de12″;
$valore=split(“[de]“,$ferro);
echo $ferro.”
“;
echo “p1-”.$valore[0].”
“;
echo “p2-”.$valore[1].”
“;
echo “p3-”.$valore[2].”
“;
This returns:
=============
2d12
p1-2
p2-
p3-12
gcerretini at technica dot net
28-Jan-2006 02:46
I’ve try using split function.
$ferro=”2?12″;
$valore=split(“[?]“,$ferro);
echo $ferro.”
“;
echo “p1-”.$valore[0].”
“;
echo “p2-”.$valore[1].”
“;
echo “p3-”.$valore[2].”
“;
$ferro=”2d12″;
$valore=split(“[d]“,$ferro);
echo $ferro.”
“;
echo “p1-”.$valore[0].”
“;
echo “p2-”.$valore[1].”
“;
echo “p3-”.$valore[2].”
“;
?>
This return:
2?12
p1-2
p2-
p3-12
2d12
p1-2
p2-12
p3-
I use charset UTF-8
When I use char ? the split function ad an empty string between “2″ and “12″ Why?
shimon at schoolportal dot co dot il
27-Dec-2005 04:34
// **
// * splitslash()
// *
// * this function enables to split with an escape char;
// *
// * @since 25/12/05 21:26:00
// * @author Shimon Doodkin
// *
// * @param $string
// * @param $string
// * @return Array()
// **
function splitslash($split,$str,$esc=’\\\\’)
{
$o=explode($split,$str);
$oc=count($o);
$a=array();
for($i=0;$i<$oc;$i++)
{
$o2=explode($esc.$esc,$o[$i]);
$o2c=count($o2);
if($o2[$o2c-1][strlen($o2[$o2c-1])-1]==$esc)
{
$o2[$o2c-1]=substr($o2[$o2c-1],0,-1);
if($i+1<$oc) { $o[$i+1]=join($esc.$esc,$o2).$split.$o[$i+1]; } else { //echo “error”; $a[]=join($esc,$o2); //do like ok } } else { $a[]=join($esc,$o2); } } return $a; } // example: $r=splitslash(“NA”,”mooNAmooNAma\\\\ma\\NA”); print_r($r); //output: /* Array ( [0] => moo
[1] => moo
[2] => ma\\maNA
)
*/
?>
04-Dec-2005 09:57
Be advised
$arr = split(“x”, “x” );
print_r($arr);
will output:
Array
(
[0] =>
[1] =>
)
That is it will catch 2 empty strings on each side of the delimiter.
franz at fholzinger dot com
04-Nov-2005 08:34
The example from ramkumar rajendran did not work.
$line = split(“/\n”, $input_several_lines_long);
I do not know why this does not work for me.
The following has worked for me to get a maximum of 2 array parts
separated by the first new line (independant if saved under UNIX or
WINDOWS):
$line = preg_split(‘/[\n\r]+/’,$input_several_lines_long,2);
Also empty lines are not considered here.
passtschu AT freenet DOT de
24-Sep-2005 03:09
divide a string with a template. the “template dividers” are the keys for the output array.
$string_match
foreach ($template_matches[1] as $key => $value){
$output[$value] = $string_matches[($key + 1)];
}
return $output;
}
$string1 = ‘www.something.com 66.196.91.121 – - [01/Sep/2005:04:20:39 +0200] “GET /robots.txt HTTP/1.0″ 200 49 “-”‘;
$string2= ‘%Domain% %IP% – %User% \[%Date%:%Time% %TimeZone%\] “%Method% %Request% %Protocol%” %ServerCode% %Bytes% “%Referer%”‘;
print_r (string2array ($string1, $string2));
/*
Array
(
[ServerAddress] => www.something.com
[IP] => 66.196.91.121
[User] => -
[Date] => 01/Sep/2005
[Time] => 04:20:39
[TimeZone] => +0200
[Method] => GET
[Request] => /robots.txt
[Protocol] => HTTP/1.0
[ServerCode] => 200
[Bytes] => 49
[Referer] => -
)
*/
?>
jh at junetz dot de
04-Jul-2005 12:34
robin: Nice function, saved my day. The +1 at the end of split / substr is wrong, though.
robin at teddyb dot org
30-Jun-2005 12:01
Actually, this version is better than the last I submitted. The goal
here is to be able to engage in *multiple* delimeter removal passes;
for all but the last pass, set the third value to “1″, and everything
should go well.
function quotesplit( $splitter=’,', $s, $restore_quotes=0 )
{
//First step is to split it up into the bits that are surrounded by quotes
//and the bits that aren’t. Adding the delimiter to the ends simplifies
//the logic further down
$getstrings = explode(‘”‘, $splitter.$s.$splitter);
//$instring toggles so we know if we are in a quoted string or not
$delimlen = strlen($splitter);
$instring = 0;
while (list($arg, $val) = each($getstrings))
{
if ($instring==1)
{
if( $restore_quotes )
{
//Add the whole string, untouched to the previous value in the array
$result[count($result)-1] = $result[count($result)-1].’”‘.$val.’”‘;
} else {
//Add the whole string, untouched to the array
$result[] = $val;
}
$instring = 0;
}
else
{
//Break up the string according to the delimiter character
//Each string has extraneous delimiters around it (inc the ones we added
//above), so they need to be stripped off
$temparray = split($splitter, substr($val, $delimlen, strlen($val)-$delimlen-$delimlen+1 ) );
while(list($iarg, $ival) = each($temparray))
{
$result[] = trim($ival);
}
$instring = 1;
}
}
return $result;
}
robin at teddyb dot org
30-Jun-2005 11:50
wchris’s quotesplit assumes that anything that is quoted must also be a
complete delimiter-seperated entry by itself. This version does not.
It also uses split’s argument order.
function quotesplit( $splitter=’,', $s )
{
//First step is to split it up into the bits that are surrounded by quotes
//and the bits that aren’t. Adding the delimiter to the ends simplifies
//the logic further down
$getstrings = explode(‘”‘, $splitter.$s.$splitter);
//$instring toggles so we know if we are in a quoted string or not
$delimlen = strlen($splitter);
$instring = 0;
while (list($arg, $val) = each($getstrings))
{
if ($instring==1)
{
//Add the whole string, untouched to the previous value in the array
$result[count($result)-1] = $result[count($result)-1].$val;
$instring = 0;
}
else
{
//Break up the string according to the delimiter character
//Each string has extraneous delimiters around it (inc the ones we added
//above), so they need to be stripped off
$temparray = split($splitter, substr($val, $delimlen, strlen($val)-$delimlen-$delimlen+1 ) );
while(list($iarg, $ival) = each($temparray))
{
$result[] = trim($ival);
}
$instring = 1;
}
}
return $result;
}
wchris
18-Feb-2005 07:53
moritz’s quotesplit didn’t work for me. It seemed to split on a comma
even though it was between a pair of quotes. However, this did work:
function quotesplit($s, $splitter=’,')
{
//First step is to split it up into the bits that are surrounded by
quotes and the bits that aren’t. Adding the delimiter to the ends
simplifies the logic further down
$getstrings = split(‘\”‘, $splitter.$s.$splitter);
//$instring toggles so we know if we are in a quoted string or not
$delimlen = strlen($splitter);
$instring = 0;
while (list($arg, $val) = each($getstrings))
{
if ($instring==1)
{
//Add the whole string, untouched to the result array.
$result[] = $val;
$instring = 0;
}
else
{
//Break up the string according to the delimiter character
//Each string has extraneous delimiters around it (inc the ones we added above), so they need to be stripped off
$temparray = split($splitter, substr($val, $delimlen, strlen($val)-$delimlen-$delimlen ) );
while(list($iarg, $ival) = each($temparray))
{
$result[] = trim($ival);
}
$instring = 1;
}
}
return $result;
}
ramkumar rajendran
18-Jan-2005 02:09
A correction to a earlier note
If you want to use split to check on line feeds (\n), the following won’t work:
$line = split(“\n”, $input_several_lines_long);
You really have to do this instead, notice the second slash:
$line = split(“/\n”, $input_several_lines_long);
Took me a little while to figure to do
claes at dot2me.com
04-Nov-2004 08:10
Though this is obvious, the manual is a bit incorrect when claiming
that the return will always be 1+number of time the split pattern
occures. If the split pattern is the first part of the string, the
return will still be 1. E.g.
$a = split(“zz,” “zzxsj.com”);
count($a);
=> 1.
The return of this can not in anyway be seperated from the return where the split pattern is not found.
moritz
10-Apr-2004 02:54
Often you want to split CSV-Like data, so this is the function for this 
It splits data formatted like:
1,2,3
-> [1,2,3]
1 , 3, 4
-> [1,3,4]
one; two;three
-> ['one','two','three']
“this is a string”, “this is a string with , and ;”, ‘this is a string
with quotes like ” these’, “this is a string with escaped quotes \” and
\’.”, 3
-> ['this is a string','this is a string with , and ;','this is a
string with quotes like " these','this is a string with escaped quotes
" and '.',3]
function quotesplit($s)
{
$r = Array();
$p = 0;
$l = strlen($s);
while ($p < $l) {
while (($p < $l) && (strpos(” \r\t\n”,$s[$p]) !== false)) $p++;
if ($s[$p] == ‘”‘) {
$p++;
$q = $p;
while (($p < $l) && ($s[$p] != ‘”‘)) {
if ($s[$p] == ‘\\’) { $p+=2; continue; }
$p++;
}
$r[] = stripslashes(substr($s, $q, $p-$q));
$p++;
while (($p < $l) && (strpos(” \r\t\n”,$s[$p]) !== false)) $p++;
$p++;
} else if ($s[$p] == “‘”) {
$p++;
$q = $p;
while (($p < $l) && ($s[$p] != “‘”)) {
if ($s[$p] == ‘\\’) { $p+=2; continue; }
$p++;
}
$r[] = stripslashes(substr($s, $q, $p-$q));
$p++;
while (($p < $l) && (strpos(” \r\t\n”,$s[$p]) !== false)) $p++;
$p++;
} else {
$q = $p;
while (($p < $l) && (strpos(“,;”,$s[$p]) === false)) {
$p++;
}
$r[] = stripslashes(trim(substr($s, $q, $p-$q)));
while (($p < $l) && (strpos(” \r\t\n”,$s[$p]) !== false)) $p++;
$p++;
}
}
return $r;
}
alphibia at alphibia dot com
31-Mar-2004 10:19
I’d like to correct myself, I found that after testing my last solution
it will create 5 lines no matter what… So I added this to make sure
that it only displays 5 if there are five newlines.
$MaxNewLines = 5;
$BRCount = substr_count($Message, ‘
‘);
if ($BRCount<$MaxNewLines)
$MaxNewLines=$BRCount;
else if($BRCount == 0)
$MaxNewLines=1;
$Message = str_replace(chr(13), ”
“, $Message);
$MessageArray = split(”
“, $Message, $MaxNewLines);
$Message = “”; $u=0;
do {
$Message.=$MessageArray[$u].’
‘;
$u++;
} while($u<($MaxNewLines-1));
$Message.=str_replace(”
“,” “,$MessageArray[$u]);
?>
-Tim
http://www.alphibia.com
nomail at please dot now
22-Nov-2003 01:33
If you want to use split to check on line feeds (\n), the following won’t work:
$line = split(“\n”, $input_several_lines_long);
You really have to do this instead, notice the second slash:
$line = split(“\\n”, $input_several_lines_long);
Took me a little while to figure out.
krahn at niehs dot nih dot gov
25-Oct-2003 03:14
> strange things happen with split
> this didn’t work
> $vontag $vonmonat were empty strings
…
> list ($vontag , $vonmonat) = split (‘.’ , $fromdate); // << bad
Split is acting exactly as it should; it splits on regular expressions.
A period is a regular expression pattern for a single character.
So, an actual period must be escaped with a backslash: ‘\.’
A period within brackets is not an any-character pattern, because it does
not make sense in that context.
Beware that regular expressions can be confusing becuase there
are a few different varieties of patterns.
dalu at uni dot de
09-Oct-2003 03:26
php4.3.0
strange things happen with split
this didn’t work
$vontag $vonmonat were empty strings
function ckdate($fromdate=”01.01″, $todate=”31.12″)
{
$nowyear = date(“Y”);
list ($vontag , $vonmonat) = split (‘.’ , $fromdate); // << bad
$vondatum = “$nowyear-$vonmonat-$vontag”;
list ($bistag , $bismonat) = split (‘.’ , $todate); // << bad
$bisdatum = “$nowyear-$bismonat-$bistag”;
$von = strtotime($vondatum);
$bis = strtotime($bisdatum);
$now = time();
if (($now <= $bis) and ($now >= $von))
{
return TRUE;
}
else
{
return FALSE;
}
}
?>
however this one worked perfectly
function ckdate($fromdate=”01.01″, $todate=”31.12″)
{
$nowyear = date(“Y”);
list ($vontag , $vonmonat) = split (‘[.]‘ , $fromdate); // << good
$vondatum = “$nowyear-$vonmonat-$vontag”;
list ($bistag , $bismonat) = split (‘[.]‘ , $todate); // << good
$bisdatum = “$nowyear-$bismonat-$bistag”;
$von = strtotime($vondatum);
$bis = strtotime($bisdatum);
$now = time();
if (($now <= $bis) and ($now >= $von))
{
return TRUE;
}
else
{
return FALSE;
}
}
?>
btw this fn checks if $now if between $fromdate and $todate
use it if you like
jeffrey at jhu dot edu
11-Jan-2003 05:51
In answer to gwyne at gmx dot net, dec 1, 2002:
For split(), when using a backslash as the delimiter, you have to *double escape* the backslash.
example:
==================================
==================================
output is:
stuff::thing:doodad:
paha at paha dot hu
22-Jul-2002 09:51
It’s evident but not mentioned in the documentation that using asterisks is more restricted than in a normal regular expression.
for exaple you cannot say:
split(“;*”,$string);
because what if there’s no “;” separator?(which is covered by this regular expression)
so you have to use at least
split(“;+”,$quotatxt);
in this situation.
fotw at gmx dot net
18-Jun-2002 03:50
Ups! It seems that neither explode nor split REALY takes a STRING but
only a single character as a string for splitting the string.
I found this problem in one of my codes when trying to split a string
using “;\n” as breaking string. The result, only “;” was thaken… the
rest of the string was ignored.
Same when I tried to substitute “\n” by any other thing. 
not at anythingspecial dot com
17-Jun-2002 09:48
If you need to do a split on a period make sure you escape the period out..
$ext_arr = split(“\.”,”something.jpg”);
… because
$ext_arr = split(“.”,”something.jpg”); won’t work properly.
kang at elpmis dot com
13-Jun-2002 02:30
This is a good way to display a comma delimited file with two columns.
The first column is the URL’s description, the second is the actual URL.
- “;
print “$desc“;
print “
$fname=”relatedlinks.csv”;
$fp=fopen($fname,”r”) or die(“Error found.”);
$line = fgets( $fp, 1024 );
while(!feof($fp))
{
list($desc,$url,$dummy) = split( “,”, $line, 3 );
print ”
\n”;
$line = fgets( $fp, 1024 );
}
fclose($fp);
?>
jchart at sdccu dot net
01-Jun-2002 03:56
[Ed. note: Close. The pipe *is* an operator in PHP, but
the reason this fails is because it's also an operator
in the regex syntax. The distinction here is important
since a PHP operator inside a string is just a character.]
The reason your code:
$line = “12|3|Fred”;
list ($msgid, $msgref, $msgtopic)=split(‘|’, $line);
didn’t work is because the “|” symbol is an operator in PHP. If you
want to use the pipe symbol as a delimiter you must excape it with a
back slash, “\|”. You code should look like this:
$line = “12|3|Fred”;
list ($msgid, $msgref, $msgtopic)=split(‘\|’, $line);
mcgarry at tig dot com dot au
17-May-2002 06:27
split() doesn’t like NUL
characters within the string, it treats the first one it meets as the
end of the string, so if you have data you want to split that can
contain a NUL character you’ll need to convert it into something else
first, eg:
$line=str_replace(chr(0),”,$line);