php substring Issue - php

Question

I have the following string:
$str = "ABACADAF";
I am using the following code:
$first2 = substr($str, 0, 2);
I want to get the following output:
output => `AB,AC,AD,AF`
(Every two characters separated by comma)
But the result I'm getting is not correct.
I checked the php manual but that is not helping, is there some foreach loop to iterate through all the string characters?

Answer 1

Not tested, but should be something along these lines:
<?php
$string = "ABACADAF";
$split = str_split($string, 2);
$implode = implode(",", $split);
echo $implode;
?>

Answer 2

You are looking for str_split function. You can do like this:
$sResult = join(',', str_split($sData, 2));
Alternatively, you can do it via regex:
$sResult = preg_replace('/(..)(?!$)/', '$1,', $sData);

Answer 3

Here's a function that you can use to output from a foreach. We're finding two capital letter matches and putting them into an array, then we implode that array() to make a string.
<?php
function splitter($string){
preg_match_all('/[A-Z]{2}/', $string, $matches);
$newstring = implode(',',$matches[0]);
return $newstring;
}
$strings = array("ABACADAF","ACABAFAC","AAABAFAD","ACACADAF");
foreach($strings as $string){
echo splitter($string)."\n";
}
?>
Output
AB,AC,AD,AF
AC,AB,AF,AC
AA,AB,AF,AD
AC,AC,AD,AF
If you're running a lot of them (millions of lines) you can use this function instead. It's much quicker.
function splitter($string){
$newstring = substr(chunk_split($string, 2, ','), 0, -1);
return $newstring;
}

Answer 4

You could do it like this or recursively as well.
<?php
for ($i=0; $i< strlen($str); $i=$i+3)
{
$str = substr($str,i,2).",".substr($str,3);
}
echo $str;
?>
I personally prefer the recursive implementation:
<?php
function add_comma($str)
{
return substr($str, 0, 2,).','.add_comma(subtr($str,3));
}
echo add_comma($str);
?>

Answer 5

While this is doable with a for loop, it is cleaner (and maybe faster), and more strait-forward in TomUnite's answer.
But since you asked...
With a for loop you could do it like this:
$withCommas = substr($string, 0, 2);
for($i=0; $i < strlen($string); $i += 2){
$withCommas+= "," . substr($string, $i, $i+2);
}

Answer 6

Here is the solution and Same output of your problem:
I personally tested it :
<?php
$str = "ABACADAF";
$first = substr($str, 0, 2);
$second = substr($str, 2, 2);
$third = substr($str, 4, 2);
$fourth = substr($str, 6, 2);
echo $output = $first.",".$second.",".$third.",".$fourth;
?>