Question

Which is the best way to do the following ?

# if I have the following string :
$str = "Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar";
# and I want to remove "o" character after 5-th match so result I need is :
$newStr = "Foo Bar Foo Bar Fo Bar F Bar F Bar F Bar F Bar...";

The way I know :

  $str = "Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar";
  $str = explode("o", $str);
  $new = "";
  $c = 1;
  foreach($str as $k) {
    if($c>5)
      $new .= $k;
    else 
      $new .= $k."o";
    $c++;
  }

I believe there is a better way of doing this.

Answer 1

There must be a million ways to do this. I had a quick scan through the built-in functions to see if there was a strpos with an n^th occurance, but there was not.

Here is a solution. It might not be the best, but who knows.

$str = "Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar";

for (
    $offset = 0, $count = 0;
    $count < 5;
    $offset = strpos($str, 'o', $offset) + 1, $count++
);

$newStr = substr($str, 0, $offset++) .
    str_replace('o', '', substr($str, $offset));

Sorry for the mad for loop, been doing too much code golf lately!

Here’s another way to do it.

$str = "Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar Foo Bar";

$newStr = implode('o', str_replace('o', '',  explode('o', $str, 6)));