SymfonyWorld Online 2022 Winter Edition

str_split

(PHP 5, PHP 7, PHP 8)

str_splitConvert a string to an array

Description

str_split(string $string, int $length = 1): array

Converts a string to an array.

Parameters

string

The input string.

length

Maximum length of the chunk.

Return Values

If the optional length parameter is specified, the returned array will be broken down into chunks with each being length in length, otherwise each chunk will be one character in length.

false is returned if length is less than 1. If the length length exceeds the length of string, the entire string is returned as the first (and only) array element.

Examples

Example #1 Example uses of str_split()

<?php

$str 
"Hello Friend";

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

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

?>

The above example will output:

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
)

Notes

Note:

str_split() will split into bytes, rather than characters when dealing with a multi-byte encoded string. Use mb_str_split() to split the string into code points.

See Also

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User Contributed Notes 1 note

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lskatz at gmail dot com
14 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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