consecutive occurrence of character - php

Question

number of consecutive occurrence of character followed by character
Ex input : 'zzzyyyyxxxwwvzz'
expected output : '3z4y3x2w1v2z'
code that i have tried
<?php
$str = "zzzyyyyxxxwwvzz";
$strArray = count_chars($str,1);
foreach ($strArray as $key=>$value)
{
echo $value.chr($key);
}
?>
output is : 5z4y3x2w1v

Answer 1

Using str_split function, get all characters in the given string in an array
Now, using basic looping and conditionals, and storing previous character, you can determine if consecutive or not, and accordingly get the output string generated.
Try the following (explanation in code comments):
$input = 'zzzyyyyxxxwwvzz';
// Split full string into array of single characters
$input_chars = str_split($input);
// initialize some temp variables
$prev_char = '';
$consecutive_count = 0;
$output = '';
// Loop over the characters
foreach ($input_chars as $char) {
// first time initialize the previous character
if ( empty($prev_char) ) {
$prev_char = $char;
$consecutive_count++;
} elseif ($prev_char === $char) { // current character matches previous character
$consecutive_count++;
} else { // not consecutive character
// add to output string
$output .= ($consecutive_count . $prev_char);
// set current char as new previous_char
$prev_char = $char;
$consecutive_count = 1;
}
}
// handle remaining characters
$output .= ($consecutive_count . $prev_char);
echo $output;
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