Replace text with preg_match_all using PHP

I have this string:

The product title is [title] and the price is [price] and this product link is 

and I have a variable called $get_product whch contain associated array.

Now, I want to replace [xxx] from the string with the $get_product[xxx] variable key. What I am doing this:

$pattern = '/\[(.*?)\]/';
preg_match_all($pattern, $optimization_prompt, $matches);

if( $matches ) {
    foreach( $matches as $key => $match ) {
        for( $i = 0; $i < count($match); $i++ ) {
            if( preg_match_all($pattern, $match[$i], $matches)  ) {
                // with bracket 
                $remove_bracket         = trim( $match[$i], '[]');
                $optimization_prompt    = str_replace( $match[$i], isset( $get_product[$remove_bracket] ) ? $get_product[$remove_bracket] : '', $optimization_prompt);
            } else {
                // Without bracket
                $remove_bracket         = trim( $match[$i], '[]');
                $optimization_prompt    = str_replace( $match[$i], '', $optimization_prompt);
            }
        }
    }
}

Its returning me:

<pre>The product  is  Infaillible Full Wear327 Cashm and the  is  10.49  and this product  is  https://www.farmaeurope.eu/infaillible-full-wear327-cashm.html</pre>

The result is okay but its removed the actual text called title, price link

It isn't a job for preg_match_all but for preg_replace_callback (it's a replacement task yes or not?).

$get_product = ['title' => 'theTitle', 'price' => 45, 'link' => 'https://thelink.com'];

$result = preg_replace_callback(
    '~\[([^][]+)]~',
    fn($m) => $get_product[$m[1]] ?? $m[0],
    $optimization_prompt
);

demo

The pattern uses a capture group (capture group 1) to extract content between square brackets. The second parameter of preg_replace_callback is the callback function that tests if the captured content $m[1] exists as key in the array $get_product and returns the corresponding value or the full match $m[0].

Other way without regex at all (since you are looking for literal strings):

$get_product = ['title' => 'theTitle', 'price' => 45, 'link' => 'https://thelink.com'];

$result = str_replace(
    array_map(fn($k) => "[$k]", array_keys($get_product)),
    $get_product,
    $optimization_prompt
);

demo

I don't know what you're trying to do there, but it's totally overcomplicated it seems. Here's a simple solution w/ comments:

$pattern = '/\[.*?\]/';
$get_product = ['title' => 'answer', 'price' => 666, 'link' => 'https://stackoverflow.com'];
$optimization_prompt = 'The product title is [title] and the price is [price] and this product link is 
';
preg_match_all($pattern, $optimization_prompt, $matches);

// Cycle through full matches
foreach($matches[0] as $match) {
	// Remove the brackets for the array key
	$product_key = trim($match, '[]');
    
    // If product key available, replace it in the text
	$optimization_prompt = str_replace($match, $get_product[$product_key] ?? '', $optimization_prompt);
}

// Result: The product title is answer and the price is 666 and this product link is https://stackoverflow.com
echo $optimization_prompt;

If you look at the result of your first preg_match_all() you will see you have all you need in the $matches array

The $matches array

Array
(
    [0] => Array
        (
            [0] => [title]
            [1] => [price]
            [2] => 

        )

    [1] => Array
        (
            [0] => title
            [1] => price
            [2] => link
        )

)

So you can simplify the code to

$get_product = ['title' => '>This is a TITLE<', 
                'price' => '>£10000.99<', 
                'link' => '>http:stackoverflow.com<'
    ];
$optimization_prompt = 'The product title is [title] and the price is [price] and this product link is 
';

$pattern = '/\[(.*?)\]/';

preg_match_all($pattern, $optimization_prompt, $matches);
print_r($matches);

foreach( $matches[0] as $i => $replace ) {
    $optimization_prompt = str_replace( $replace, $get_product[$matches[1][$i]], $optimization_prompt);
}

echo $optimization_prompt;

And the result is

The product title is >This is a TITLE< and the price is >£10000.99< and this product link is >http:stackoverflow.com<

</details>



# 答案4
**得分**: 0

添加一些调试行应该会有帮助：

<?php

$optimization_prompt = ''The product title is [title] and the price is [price] and this product link is

$pattern = ''/[(.*?)]/';
preg_match_all($pattern, $optimization_prompt, $matches);

if( $matches ) {
foreach( $matches as $key => $match ) {
for( $i = 0; $i < count($match); $i++ ) {
if( preg_match_all($pattern, $match[$i], $matches) ) {
// with bracket
$remove_bracket = trim( $match[$i], ''[]');
print "WITH Replace -$match[$i]-:". (isset( $get_product[$remove_bracket] ) ? $get_product[$remove_bracket] : '').":" .PHP_EOL;
$optimization_prompt = str_replace( $match[$i], isset( $get_product[$remove_bracket] ) ? $get_product[$remove_bracket] : '', $optimization_prompt);
} else {
// Without bracket
$remove_bracket = trim( $match[$i], ''[]');
print "WITHOUT Replace -$match[$i]-: " . '' .":".PHP_EOL;
$optimization_prompt = str_replace( $match[$i], '', $optimization_prompt);
}
}
}
}

print $optimization_prompt;

output:

WITH Replace -[title]-:TITLE:
WITH Replace -[price]-:PRICE:
WITH Replace -

<details>
<summary>英文:</summary>

Adding some debug lines should help:

<?php

$optimization_prompt = 'The product title is [title] and the price is [price] and this product link is

$pattern = '/[(.*?)]/';
preg_match_all($pattern, $optimization_prompt, $matches);

if( $matches ) {
foreach( $matches as $key => $match ) {
for( $i = 0; $i < count($match); $i++ ) {
if( preg_match_all($pattern, $match[$i], $matches) ) {
// with bracket
$remove_bracket = trim( $match[$i], '[]');
print "WITH Replace -$match[$i]-:". (isset( $get_product[$remove_bracket] ) ? $get_product[$remove_bracket] : '').":" .PHP_EOL;
$optimization_prompt = str_replace( $match[$i], isset( $get_product[$remove_bracket] ) ? $get_product[$remove_bracket] : '', $optimization_prompt);
} else {
// Without bracket
$remove_bracket = trim( $match[$i], '[]');
print "WITHOUT Replace -$match[$i]-: ". '' .":".PHP_EOL;
$optimization_prompt = str_replace( $match[$i], '', $optimization_prompt);
}
}
}
}

print $optimization_prompt;

output:

WITH Replace -[title]-:TITLE:
WITH Replace -[price]-:PRICE:
WITH Replace -

Here: `WITHOUT Replace -title-: :` means that the text between `-` is replaced by the text between `:`, effectively removing the text `title`.

</details>