Determine repeat characters in a php string - php

Question

I have found many examples of how to find repeat characters in a string. I believe my requirement is unique.
I have string
$string=aabbbccddd;
I need to determine which character was repeated the most.
So for the above example it would say
The character repeated the most is "B".
However in the example above both B and D are repeated 3 times.
Would need to spot that. B AND D are both repeated 3 times.
This is what I have so far. FAR from what I need but starting point
<?php
$string = "aabbbccddd";
$array=array($array);
foreach (count_chars($string, 1) as $i => $val) {
$count=chr($i);
$array[]= $val.",".$count;
}
print_r($array);
?>
Anyone have any thing that could help me?

Answer 1

Based on georg's great point, I would use a regex. This will handle split duplicates like ddaaddd with array keys dd=>2 and ddd=>3 but will only show one entry for dd when given ddaadd. To represent both would require a more complex array:
$string = "ddaabbbccddda";
preg_match_all('/(.)\1+/', $string, $matches);
$result = array_combine($matches[0], array_map('strlen', $matches[0]));
arsort($result);
If you only need a count of ALL occurrences try:
$result = array_count_values(str_split($string));
arsort($result);
Legacy Answers:
If you don't have split duplicates:
$string = 'aabbbccddd';
$letters = str_split($string);
$result = array_fill_keys($letters, 1);
$previous = '';
foreach($letters as $letter) {
if($letter == $previous) {
$result[$letter]++;
}
$previous = $letter;
}
arsort($result);
print_r($result);
Or for a regex approach:
preg_match_all('/(.)\1+/', $string, $matches);
$result = array_combine($matches[1], array_map('strlen', $matches[0]));
arsort($result);

Answer 2

Here's exactly what your looking for :
<?php
function printCharMostRepeated($str)
{
if (!empty($str))
{
$max = 0;
foreach (count_chars($str, 1) as $key => $val)
if ($max < $val) {
$max = $val;
$i = 0;
unset($letter);
$letter[$i++] = chr($key);
} else if ($max == $val)
$letter[$i++] = chr($key);
if (count($letter) === 1)
echo 'The character the most repeated is "'.$letter[0].'"';
else if (count($letter) > 1) {
echo 'The characters the most repeated are : ';
$count = count($letter);
foreach ($letter as $key => $value) {
echo '"'.$value.'"';
echo ($key === $count - 1) ? '.': ', ';
}
}
} else
echo 'value passed to '.__FUNCTION__.' can\'t be empty';
}
$str = 'ddaabbccccsdfefffffqqqqqqdddaaa';
printCharMostRepeated($str);

Answer 3

use count-chars()
http://php.net/manual/en/function.count-chars.php
and then asort()
http://php.net/manual/en/function.asort.php

Answer 4

<?php
$word = "abcdefghbi";
for($i=0; $i<strlen($word);$i++){
for($k=0;$k<strlen($word);$k++){
if($word[$i] == $word[$k] && $i != $k){
echo $word[$k]." is duplicate";
exit;
}
}
}
echo "no match found";
?>

Answer 5

$data = "aabbbcccdddz";
$array = str_split($data);
$v = array_count_values($array);
foreach($v as $k => $val){
echo $k.' = '.$val.'<br>';
}