SunshinePHP Developer Conference 2015

str_split

(PHP 5)

str_split Converte una stringa in una matrice

Descrizione

array str_split ( string $string [, int $split_length ] )

Converte una stringa in una matrice. Se viene passato il parametro opzionale split_length, la matrice restituita sarà composta da segmenti, ciascuno della lunghezza di split_length caratteri, in caso contrario ciascun segmento sarà lungo un carattere.

FALSE è restituito se split_length è minore di 1. Se split_length supera la lunghezza di string, sarà restituita l'intera stringa come primo (ed unico) elemento della matrice.

Example #1 Esempi di uso di str_split()

<?php

$str 
"Hello Friend";

$arr1 str_split($str);
$arr2 str_split($str3);

print_r($arr1);
print_r($arr2);

?>

L'output potrà essere:

Array
(
    [0] => H
    [1] => e
    [2] => l
    [3] => l
    [4] => o
    [5] =>
    [6] => F
    [7] => r
    [8] => i
    [9] => e
    [10] => n
    [11] => d
)

Array
(
    [0] => Hel
    [1] => lo 
    [2] => Fri
    [3] => end
)

Example #2 Esempi relativi a str_split()

<?php

$str 
"Hello Friend";

echo 
$str{0};  // H
echo $str{8};  // i

// Creates: array('H','e','l','l','o',' ','F','r','i','e','n','d')
$arr1 preg_split('//'$str, -1PREG_SPLIT_NO_EMPTY);

?>

Vedere anche: chunk_split(), preg_split(), split(), count_chars(), str_word_count() e for.

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User Contributed Notes 35 notes

up
27
qeremy [atta] gmail [dotta] com
2 years ago
A proper unicode string split;

<?php
function str_split_unicode($str, $l = 0) {
    if (
$l > 0) {
       
$ret = array();
       
$len = mb_strlen($str, "UTF-8");
        for (
$i = 0; $i < $len; $i += $l) {
           
$ret[] = mb_substr($str, $i, $l, "UTF-8");
        }
        return
$ret;
    }
    return
preg_split("//u", $str, -1, PREG_SPLIT_NO_EMPTY);
}
?>

$s = "Ilık süt"; // Mild milk

print_r(str_split($s, 3));
print_r(str_split_unicode($s, 3));

Array
(
    [0] => Il�
    [1] => �k
    [2] => sü
    [3] => t
)

Array
(
    [0] => Ilı
    [1] => k s
    [2] => üt
)
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7
anon
4 years ago
I needed a function that could split a string from the end with any left over chunk being at the beginning of the array (the beginning of the string).

<?php
function str_rsplit($str, $sz)
{
   
// splits a string "starting" at the end, so any left over (small chunk) is at the beginning of the array.   
   
if ( !$sz ) { return false; }
    if (
$sz > 0 ) { return str_split($str,$sz); }    // normal split
   
   
$l = strlen($str);
   
$sz = min(-$sz,$l);
   
$mod = $l % $sz;
   
    if ( !
$mod ) { return str_split($str,$sz); }    // even/max-length split

    // split
   
return array_merge(array(substr($str,0,$mod)), str_split(substr($str,$mod),$sz));
}

$str = 'aAbBcCdDeEfFg';
str_split($str,5); // return: {'aAbBc','CdDeE','fFg'}
str_rsplit($str,5); // return: {'aAbBc','CdDeE','fFg'}
str_rsplit($str,-5); // return: {'aAb','BcCdD','eEfFg'}

?>
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3
rrelmy
6 years ago
revised function from tatsudoshi

Fixed some bugs, more php5 style compliant
<?php
if(!function_exists('str_split')) {
    function
str_split($string,$string_length=1) {
        if(
strlen($string)>$string_length || !$string_length) {
            do {
               
$c = strlen($string);
               
$parts[] = substr($string,0,$string_length);
               
$string = substr($string,$string_length);
            } while(
$string !== false);
        } else {
           
$parts = array($string);
        }
        return
$parts;
    }
}
?>
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3
vec [ at t] g dot com
6 years ago
the fastast way (that fits my needs) to replace str_split() in php 4 i found is this:

<?php
if(!function_exists('str_split')) {
  function
str_split($string, $split_length = 1) {
   
$array = explode("\r\n", chunk_split($string, $split_length));
   
array_pop($array);
    return
$array;
  }
}
?>

i also tested the provided functions in the comments..

(the differences are 0.001 to 0.00001 sec)
up
3
dacmeaux at gmail dot com
6 years ago
I was looking for a function that would split a string into an array like str_split() and found Razor's function above. Just though that I would simplify the code a little.

<?php
function str_split_php4($text, $split = 1){
   
//place each character of the string into and array
   
$array = array();
    for(
$i=0; $i < strlen($text); $i++){
       
$key = NULL;
        for (
$j = 0; $j < $split; $j++){
           
$key .= $text[$i]; 
        }
       
array_push($array, $key);
    }
    return
$array;
}
?>

Both mine and worksRazor's work well, I just prefer to use less code. I could have written one myself, but I was just being lazy.
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3
Anonymous
6 years ago
Version of str_split by rlpvandenberg at hotmail dot com is god-damn inefficient and when $i+$j > strlen($text) [last part of string] throws a lot of notice errors. This should work better:

    if(! function_exists('str_split'))
    {
        function str_split($text, $split = 1)
        {
            $array = array();
           
            for ($i = 0; $i < strlen($text);)
            {
                $array[] = substr($text, $i, $split);
                $i += $split;
            }
           
            return $array;
        }
    }
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2
nemostein at hotmail dot com
5 years ago
The manual don't says what is returned when you parse a different type of variable.

This is the example:

<?php

$str1
= "Long"; // More than 1 char
$str2 = "x"; // Only 1 char
$str3 = ""; // Empty String
$str4 = 34; // Integer
$str5 = 3.4; // Float
$str6 = true; // Bool
$str7 = null; // Null

$spl1 = str_split($str1);
$spl2 = str_split($str2);
$spl3 = str_split($str3);
$spl4 = str_split($str4);
$spl5 = str_split($str5);
$spl6 = str_split($str6);
$spl7 = str_split($str7);

echo
count($spl1); // 4
echo count($spl2); // 1
echo count($spl3); // 1
echo count($spl4); // 2
echo count($spl5); // 3
echo count($spl6); // 1
echo count($spl7); // 1

print_r($spl1);
print_r($spl2);
print_r($spl3);
print_r($spl4);
print_r($spl5);
print_r($spl6);
print_r($spl7);

/*

Array
(
    [0] => L
    [1] => o
    [2] => n
    [3] => g
)
Array
(
    [0] => x
)
Array
(
    [0] =>
)
Array
(
    [0] => 3
    [1] => 4
)
Array
(
    [0] => 3
    [1] => .
    [2] => 4
)
Array
(
    [0] => 1
)
Array
(
    [0] =>
)

*/

?>
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2
fstorm2 at gmail dot com
8 years ago
If you use PHP 4 and don't need the split_length parameter, here's the shortest replacement:

<?php

preg_split
('#(?<=.)(?=.)#s', $str);

?>
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1
kevin at metalaxe dot com
6 years ago
Response to "Richard Ayotte 18-Jan-2008 09:27":

Slight tweak to prevent the need to call another preg_replace, there were also some bugs in this that I'm surprised didn't get noticed (causing duplicate replaces between the preg_replace calls) :)

Please feel free to optimize further. I'm not the best with lookahead/behinds yet. I also removed the :upper/lower: and it seemed to speed things up too.

<?php
$test
= 'CustomerIDWithSomeOtherJETWords';

preg_replace('/(?!^)[A-Z]{2,}(?=[A-Z][a-z])|[A-Z][a-z]/', ' $0', $test));
?>

Shaves off a little time anyway. :)
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1
Sam
7 years ago
A good way to use this method to convert CamelCase text into nice text would be-

<?php
       
/**
         Returns a formatted string based on camel case.
         e.g. "CamelCase" -> "Camel Case".
        */
       
function FormatCamelCase( $string ) {
               
$output = "";
                foreach(
str_split( $string ) as $char ) {
                       
strtoupper( $char ) == $char and $output and $output .= " ";
                       
$output .= $char;
                }
                return
$output;
        }
?>
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0
kunal dot b at indiaproperty dot com
26 days ago
Note that in atleast in PHP 5.5.9 (Zend Engine v2.5.0), str_split with an integer value as an argument may return unpredictable results.

If your number contains leading 0's, the result array is unprdictable as it may contain any number of digits from the argument or (mostly) just a 0.

Here are a list of possible values that might be returned:
-Interger

<?php
print_r
(str_split(0080450));  // does not work
print_r(str_split(strval(0080450)));  // neither this

/*
* Outputs:
* Array
* (
*     [0] => 0
* )
*/
?>

BUT
<?php
print_r
(str_split(80450));  // works fine
print_r(str_split(strval(80450)));  // so does this

/*
* Outputs:
* (
*     [0] => 8
*     [1] => 0
*     [2] => 4
*     [3] => 5
*     [4] => 0
* )
*/
?>

Floating point numbers have their leading and trailing 0s cut off:
<?php
print_r
(str_split(0080450.0010));   // works but.. print_r(str_split(strval(0080450.0010)));  // same here..

/*
Outputs:
* Array
* (
*     [0] => 8
*     [1] => 0
*     [2] => 4
*     [3] => 5
*     [4] => 0
*     [5] => .
*     [6] => 0
*     [7] => 0
*     [8] => 1
* )
*/
?>

I'm not sure if this can be considered a bug, since this is due to how type conversion and casting works, so i just posted it here.
I've notced that this is how strval() works. Can anyone shed light into this?..
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0
robert dot johnson at icap dot com
1 month ago
<?php
/* Another implementation of str_split_unicode: */
function str_split_unicode($str, $l = 0)
{
    return
preg_split('/(.{'.$l.'})/us', $str, -1, PREG_SPLIT_NO_EMPTY|PREG_SPLIT_DELIM_CAPTURE);
}
?>
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0
jakub dot lopuszanski at nasza-klasa dot pl
1 year ago
To split UTF-8 into 16-charcater slices you can use:
<?php
preg_split
('/(?=(.{16})*$)/u', $text);
?>
You can also use look-behind instead of look-ahead if you want the first (not the last) chunk to be the shortest.
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0
stlawson AT JoyfulEarthTech DOT com
1 year ago
The documentation fails to mention what happens when the string length does not divide evenly with the chunk size.  Not sure if the same behavior for all versions of PHP so I offer the following code to determine this for your installation.  On mine [version 5.2.17], the last chunk is an array the length of the remaining chars.

<?php

$da_string
= "When number of chars does't divide evenly";
$len = strlen($da_string);
$chunk_size = 8;
echo
"<p> Length of <span style='font-family:monospace'>$da_string</span>: $len</p>\n";
echo
"<p> Chunck size: $chunk_size</p>\n";
$parts = str_split($da_string, $chunk_size);
$html = "<table border='5' cellpadding='3' cellspacing='4'>\n";
foreach (
$parts as $idx=>$part)
{
  
$html .= "<tr>\n";
  
$html .= "<td style='font-family:monospace'>$part</td>";
  
$chars = str_split($part);
   foreach (
$chars as $char)
   {
       if (
$char === ' ')
       {
          
$html .= "<td>&nbsp;</td>";
       }
       else
       {
          
$html .= "<td>$char</td>";
       }
   }
  
$html .= "</tr>\n";
}
$html .= "</table>\n";
echo
$html;
?>
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1
kjensen at iaff106 dot com
7 years ago
Here is what I use. I started with examples here but modified to my own version:

<?php
if (phpversion () < "5"){ // define PHP5 functions if server uses PHP4

function str_split($text, $split = 1)
{
if (!
is_string($text)) return false;
if (!
is_numeric($split) && $split < 1) return false;
$len = strlen($text);
$array = array();
$s = 0;
$e=$split;
while (
$s <$len)
    {
       
$e=($e <$len)?$e:$len;
       
$array[] = substr($text, $s,$e);
       
$s = $s+$e;
    }
return
$array;
}
}
?>
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1
webmaster at nsssa dot ca
7 years ago
I noticed in the post below me that his function would return an array with an empty key at the end.

So here is just a little fix for it.

<?php

//Create a string split function for pre PHP5 versions
function str_split($str, $nr) {  
            
    
//Return an array with 1 less item then the one we have
    
return array_slice(split("-l-", chunk_split($str, $nr, '-l-')), 0, -1);
     
}

?>
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0
seebz.net
4 years ago
here an equivalent function for unicode string :

<?php
function uni_strsplit($string, $split_length=1)
{
   
preg_match_all('`.`u', $string, $arr);
   
$arr = array_chunk($arr[0], $split_length);
   
$arr = array_map('implode', $arr);
    return
$arr;
}
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0
thax
5 years ago
Regarding ricordatis comment on preg_match_all('/./u',...) instead of preg_split('//u',...):
You'll have to use the pattern '/./us' with preg_match_all to get exactly the same behaviour w.r.t. newlines. Don't know if this is still faster, though. Oh, and the expected result is in $array[0].
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0
saeedco
6 years ago
This function supportes utf8

(improvement of function str_split_php4)

i tried this function successfully with these languages
1- Chinese
2- Japanese
3- Arabic
4- Turkish
5- Urdu
6- Russian
7- Persian

<?php
function str_split_php4_utf8($str) {
   
// place each character of the string into and array
   
$split=1;
   
$array = array();
    for (
$i=0; $i < strlen( $str ); ){
       
$value = ord($str[$i]);
        if(
$value > 127){
            if(
$value >= 192 && $value <= 223)
               
$split=2;
            elseif(
$value >= 224 && $value <= 239)
               
$split=3;
            elseif(
$value >= 240 && $value <= 247)
               
$split=4;
        }else{
           
$split=1;
        }
           
$key = NULL;
        for (
$j = 0; $j < $split; $j++, $i++ ) {
           
$key .= $str[$i];
        }
       
array_push( $array, $key );
    }
    return
$array;
}
?>
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0
rlpvandenberg at hotmail dot com
6 years ago
The previous suggestion is almost correct (and will only working for strlen=1. The working PHP4 function is:

<code>
function str_split($text, $split = 1){
    //place each character of the string into and array
    $array = array();
    for ($i=0; $i < strlen($text); $i++){
        $key = "";
        for ($j = 0; $j < $split; $j++){
            $key .= $text[$i+$j]; 
        }
        $i = $i + $j - 1;
        array_push($array, $key);
    }
    return $array;
}
</code>
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0
mohd at ba7rain dot net
6 years ago
this function can perform a reverse str_split. I write it for PHP4 but you can rename It for other versions..

if ( !function_exists('str_split') ) {
function str_split($string,$split_length=1){
    $sign = (($split_length<0)?-1:1);
    $strlen = strlen($string);
    $split_length = abs($split_length);
    if ( ($split_length==0) || ($strlen==0) ){
            $result = false;
            //$result[] = "";
    }
    elseif ($split_length >= $strlen){
        $result[] = $string;
    }
    else {
        $length = $split_length;
        for ($i=0; $i<$strlen; $i++){
            $i=(($sign<0)?$i+$length:$i);
            $result[] = substr($string,$sign*$i,$length);
            $i--;
            $i=(($sign<0)?$i:$i+$length);
            if ( ($i+$split_length) > ($strlen) ){
                $length = $strlen-($i+1);
            }
            else {
                $length = $split_length;
            }
        }
    }
    return $result;
}
}
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0
atolia at gmail----- dot com
6 years ago
i use this in PHP4

function str_split($str){
   return preg_split('//',$str);
}
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0
magisano at cs dot unibo dot it
6 years ago
Even shorter version:

//place each character (or group of) of the
string into and array

function str_split_php4($sText, $iSplit = 1)
{
    $iSplit=(integer) $iSplit;       // sanity check
    if ($iSplit < 1) {  return false; }
    $aResult = array();
    for($i=0, $limit=strlen($sText); $i < $limit; $i+=$iSplit) {
        $aResult[]=substr($sText, $i, $iSplit);
    }
    return $aResult;
}
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0
Razor
7 years ago
heres my version for php4 and below

<?php

function str_split_php4($text, $split = 1)
{
    if (!
is_string($text)) return false;
    if (!
is_numeric($split) && $split < 1) return false;
   
   
$len = strlen($text);
   
   
$array = array();
   
   
$i = 0;
   
    while (
$i < $len)
    {
       
$key = NULL;
       
        for (
$j = 0; $j < $split; $j += 1)
        {
           
$key .= $text{$i};
           
           
$i += 1;   
        }
       
       
$array[] = $key;
    }
   
    return
$array;
}

?>
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0
malmsteenforce at tlen dot pl
8 years ago
<?
//fast & short version od str_split

function string_split($str)
      {
       
$str_array=array();
       
$len=strlen($str);
        for(
$i=0;$i<$len;$i++) $str_array[]=$str{$i};
        return
$str_array;
       }
//example :
var_dump (string_split("split this"));
?>
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0
user at mockme dot com
8 years ago
found this great example on a php board for those not using php5, as an alternative to the posts below this

<?php
if(!function_exists('str_split')){
    function
str_split($string,$split_length=1){
       
$count = strlen($string); 
        if(
$split_length < 1){
            return
false
        } elseif(
$split_length > $count){
            return array(
$string);
        } else {
           
$num = (int)ceil($count/$split_length); 
           
$ret = array(); 
            for(
$i=0;$i<$num;$i++){ 
               
$ret[] = substr($string,$i*$split_length,$split_length); 
            } 
            return
$ret;
        }     
    } 
}
?>
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0
heavyraptor
8 years ago
I think that the last post by carlosreche at yahoo dot com is too complicated.
It's much easier if you do it like this:

<?php
if (!function_exists("str_split")) {
  function
str_split($str,$length = 1) {
    if (
$length < 1) return false;
   
$strlen = strlen($str);
   
$ret = array();
    for (
$i = 0; $i < $strlen; $i += $length) {
    
$ret[] = substr($str,$i,$length);
    }
    return
$ret;
  }
}
?>

I hope it helps for those with PHP <5
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0
carlosreche at yahoo dot com
8 years ago
For those who work with PHP < 5:

<?php

if (!function_exists("str_split")) {
    function
str_split($string, $length = 1) {
        if (
$length <= 0) {
           
trigger_error(__FUNCTION__."(): The the length of each segment must be greater then zero:", E_USER_WARNING);
            return
false;
        }
       
$splitted  = array();
       
$str_length = strlen($string);
       
$i = 0;
        if (
$length == 1) {
            while (
$str_length--) {
               
$splitted[$i] = $string[$i++];
            }
        } else {
           
$j = $i;
            while (
$str_length > 0) {
               
$splitted[$j++] = substr($string, $i, $length);
               
$str_length -= $length;
               
$i += $length;
            }
        }
        return
$splitted;
    }
}

?>
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0
Hage Yaapa
8 years ago
The very handy str_split() was introduced in PHP 5, but a lot of us are still forced to use PHP 4 at our host servers. And I am sure a lot of beginners have looked or are looking for a function to accomplish what str_split() does.

Taking advantge of the fact that strings are 'arrays' I wrote this tiny but useful e-mail cloaker in PHP, which guarantees functionality even if JavaScript is disabled in the client's browser. Watch how I make up for the lack of str_split() in PHP 4.3.10.

<?php

// cloackEmail() accepts a string, the email address to be cloaked
function cloakEmail($email) {

// We create a new array called $arChars, which will contain the individula characters making up the email address. The array is blank for now.
   
$arChars = array();

// We extract each character from the email 'exploiting' the fact that strings behave like an array: watch the '$email[$i]' bit, and beging to fill up the blank array $arChars
   
for ($i = 0; $i < strlen($email); $i++) { $arChars[] = $email[$i]; }

// Now we work on the $arChars array: extract each character in the array and print out it's ASCII value prefixed with '&#' to convert it into an HTML entity
   
foreach ($arChars as $char) { print '&#'.ord($char); }

// The result is an email address in HTML entities which, I hope most email address harvesters can't read.

}
print
cloakEmail('someone@nokikon.com');
?>

###### THE CODE ABOVE WITHOUT COMMENTS ######

<?php
function cloakEmail($email) {
   
$arChars = array();
    for (
$i = 0; $i < strlen($email); $i++) { $arChars[] = $email[$i]; }
    foreach (
$arChars as $char) { print '&#'.ord($char); }
}
print
cloakEmail('someone@nokikon.com');
?>

In creating this little utility, I demonstrated how the lack of str_split() can be made up in PHP < 5. If you got how it was accomplished, you could write a function to do exactly what str_split() does in PHP 5 and even name it 'str_split()'. :)
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-2
qeremy [atta] gmail [dotta] com
1 year ago
A new version of "str_split_unicode" prev.

<?php
function str_split_unicode($str, $length = 1) {
   
$tmp = preg_split('~~u', $str, -1, PREG_SPLIT_NO_EMPTY);
    if (
$length > 1) {
       
$chunks = array_chunk($tmp, $length);
        foreach (
$chunks as $i => $chunk) {
           
$chunks[$i] = join('', (array) $chunk);
        }
       
$tmp = $chunks;
    }
    return
$tmp;
}
?>

$s = 'Özgür Yazılım!'; // Open Source!

print_r(str_split_unicode($s));
print_r(str_split_unicode($s, 3));

Array
(
    [0] => Ö
    [1] => z
    [2] => g
    [3] => ü
    [4] => r
    [5] => 
    [6] => Y
    [7] => a
    [8] => z
    [9] => ı
    [10] => l
    [11] => ı
    [12] => m
    [13] => !
)
Array
(
    [0] => Özg
    [1] => ür
    [2] => Yaz
    [3] => ılı
    [4] => m!
)
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-1
l0c4lh0st DOT nl AT gmail DOT com
7 years ago
how I can conwert
$string
'1, 2, 5, 6, 10, 13, 23'
from ENUM at mySQL to

$array
[0] -> false
[1] -> true
[2] -> true
[3] -> false
[4] -> false
[5] -> true
[6] -> true
[7] -> false
[8] -> false
[9] -> false
[10] -> true
[11] -> false
[12] -> false
[13] -> true
[14] -> false
[15] -> false
...
[23] -> true

<?php
function enum_to_array($psEnum)
{
   
$aReturn = array();
   
$aTemp = explode(', ', $psEnum);
    for (
$i = $aTemp[0]; $i <= $aTemp[count($aTemp)-1]; $i++)
    {
       
$aReturn[$i] = in_array($i, $aTemp);
    }
}
?>
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-1
lskatz at gmail dot com
6 years ago
A good use of str_split is reverse translating an amino acid sequence.

<?php
/* reverse translate an aa sequence using its dna counterpart */
function reverseTranslate($aaSeq,$ntSeq){
 
$nt=str_split($ntSeq,3);
 
$aa=str_split($aaSeq,1);
 
$gapChar=array('*','-');

 
$numAa=count($aa);
 
$ntIndex=0;
 
$newNtSeq="";
  for(
$i=0;$i<$numAa;$i++){
   
// if the aa is a gap, then just put on a gap character
   
if(in_array($aa[$i],$gapChar)){
     
$newNtSeq.='---';
    }
    else{
     
$newNtSeq.=$nt[$ntIndex];
     
$ntIndex++;
    }
  }
  return
$newNtSeq;
}
?>
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-2
mattias at lsahlin dot se
5 years ago
For those it may concern:

We encountered trubble when trying to str_split a UTF-8 encoded string, containing such Swedish letters as å, å and ö.

It seems that this function splits according to byte-length and not character length. So if the letter "Å" takes 2 bytes, then str_split() will only return the first bite of the character "Å".

We ain't 100% sure that this is the case but this was anyhow the result we got. So we used the multi-byte functions instead.
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-2
Anonymous
2 years ago
A little one-liner that came in handy. I thought i'd share for those who want to split a string into two parts by the given offset.

<?php

   
/**
    * Split a string into two parts at offset.
    *
    * @param    string    $string
    * @param    integer    $offset
    * @return    mixed    array and bool(false) if offset is out of scope
    */

function str_osplit($string, $offset){
    return isset(
$string[$offset]) ? array(substr($string, 0, $offset), substr($string, $offset)) : false;
    }

$str = "Split a string into two parts at offset";
var_dump(str_osplit($str, 12));

/**
* Output:
array(2) {
  [0]=>
  string(12) "Split a stri"
  [1]=>
  string(27) "ng into two parts at offset"
}
*/

?>
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-2
ricordati at web dot de
6 years ago
To split unicode text, preg_match_all('/./u', $text, $array); seems faster for large strings than the use of preg_split('//u', $text); suggested by "edgaras dot janusauskas at gmail dot com" below.
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