php - How to style a character in a string at specific index? -

would please give me guidance on how style 1 character in string @ specific index? index of string comes array , in cases array empty, need style character in string if array not empty

$indices = array(74, 266);   $string  = "caggacactctttctagtgttgattcacctcgaagaaggtctggcctattaagagatcaagttcagttggtaaaaagaagcaactctgctcgttatgagatagtcccgattcaagatcaactatcatttgagaagggtttctttattgtaatccgtgcatgccagttgttggctcagaagaatgaaggcattgtactggtgggagtcgctggtccttcaggggccggaaagaccatgtttacagaaaagatcctgaatgttatgcctagtattgcaatcataaacatggacaactacaatgatcccagtcgtatcattgatggaaacttcgacg"; 

so how add surround character @ index 74 , 266 span can give different style?

my data coming database need make dynamic.

thanks

it's easy: need few substrs in loop , keep track of character count.

here's working code made:

// zero-based indices $indices = array(3, 10, 25);  // input $in = 'abcdefghijklmnopqrstuvwxyz';  $opentag = '<b>'; $closetag = '</b>';  $out = ''; $last = 0; foreach($indices $i) {     $fragment = substr($in, $last, $i-$last);     $letter = substr($in, $i, 1);     $last = $i+1;      $out .= $fragment . $opentag . $letter . $closetag; }  $out .= substr($in, $last);  // output echo $out; 

for example, $out abc<b>d</b>efghij<b>k</b>lmnopqrstuvwxy<b>z</b>.

---

for convenience, here's as function:

function highlightchars($text, $indices, $opentag, $closetag) {     $out = '';     $last = 0;     foreach($indices $i) {         $fragment = substr($text, $last, $i-$last);         $letter = substr($text, $i, 1);         $last = $i+1;          $out .= $fragment . $opentag . $letter . $closetag;     }      $out .= substr($text, $last);      return $out; }