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
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;