Replace multiple occurrences of a string with different values

问题

I have a script that generates content containing certain tokens, and I need to replace each occurrence of a token, with different content resulting from a separate loop.

It's simple to use str_replace to replace all occurrences of the token with the same content, but I need to replace each occurrence with the next result of the loop.

I did see this answer: Search and replace multiple values with multiple/different values in PHP5?

however it is working from pre-defined arrays, which I don't have.

Sample content:

This is an example of %%token%% that might contain multiple instances of a particular
%%token%%, that need to each be replaced with a different piece of %%token%% generated 
elsewhere.

I need to replace each occurrence of %%token%% with content generated, for argument's sake, by this simple loop:

for($i=0;$i<3;$i++){
    $token = rand(100,10000);
}

So replace each %%token%% with a different random number value $token.

Is this something simple that I'm just not seeing?

Thanks!

回答1:

I don't think you can do this using any of the search and replace functions, so you'll have to code up the replace yourself.

It looks to me like this problem works well with explode(). So, using the example token generator you provided, the solution looks like this:

$shrapnel = explode('%%token%%', $str);
$newStr = '';
for ($i = 0; $i < count($shrapnel); ++$i)  {
    // The last piece of the string has no token after it, so we special-case it
    if ($i == count($shrapnel) - 1)
        $newStr .= $shrapnel[$i];
    else
        $newStr .= $shrapnel[$i] . rand(100,10000);
}

回答2:

I know this is an old thread, but I stumbled across it while trying to achieve something similar. If anyone else sees this, I think this is a little nicer:

Create some sample text:

$text="This is an example of %%token%% that might contain multiple instances of a particular
%%token%%, that need to each be replaced with a different piece of %%token%% generated 
elsewhere.";

Find the search string with regex:

$new_text = preg_replace_callback("|%%token%%|", "_rand_preg_call", $text);

Define a callback function to change the matches

function _rand_preg_call($matches){
  return rand(100,10000);
}

Echo the results:

echo $new_text;

So as a function set:

function _preg_replace_rand($text,$pattern){
  return preg_replace_callback("|$pattern|", "_rand_preg_call", $text);
}

function _rand_preg_call($matches){
  return rand(100,10000);
}

回答3:

I had a similar issue where I had a file that I needed to read. It had multiple occurrences of a token, and I needed to replace each occurrence with a different value from an array.

This function will replace each occurrence of the "token"/"needle" found in the "haystack" and will replace it with a value from an indexed array.

function mostr_replace($needle, $haystack, $replacementArray, $needle_position = 0, $offset = 0)
{
    $counter = 0;
    while (substr_count($haystack, $needle)) {

        $needle_position = strpos($haystack, $needle, $offset);
        if ($needle_position + strlen($needle) > strlen($haystack)) {
            break;
        }
        $haystack = substr_replace($haystack, $replacementArray[$counter], $needle_position, strlen($needle));
        $offset = $needle_position + strlen($needle);
        $counter++;
    }

    return $haystack;
}

By the way, 'mostr_replace' is short for "Multiple Occurrence String Replace".

回答4:

You can use the following code:

$content = "This is an example of %%token%% that might contain multiple instances of a particular %%token%%, that need to each be replaced with a different piece of %%token%% generated elsewhere.";

while (true)
{
    $needle = "%%token%%";
    $pos = strpos($content, $needle);
    $token = rand(100, 10000);
    if ($pos === false)
    {
        break;
    }
    else
    {
        $content = substr($content, 0,
                          $pos).$token.substr($content, $pos + strlen($token) + 1);
    }
}

来源：https://stackoverflow.com/questions/7543821/replace-multiple-occurrences-of-a-string-with-different-values