CODEWITHSUNDEEP
phpregex
Vishesh Joshi
Vishesh Joshi

Reputation: 1611

Parse through a string php and replace substrings

I have a string, in PHP and the string has occurrences of the pattern %%abc%%(some substring)%%xyz%%

There are multiple occurrences of such substrings within the master string. Each of these occurrences need to be replaced with a string from within an array array('substring1','substring2','substring3','substring4') depending upon the response of a function() which returns back a integer between 1 to 4.

I am not able to figure out an efficient way to do this.

Upvotes: 2

Views: 134

Answers (2)

Jon
Jon

Reputation: 437424

This is a situation that calls for preg_replace_callback:

// Assume this already exists
function mapSubstringToInteger($str) {
    return (strlen($str) % 4) + 1;
}

// So you can now write this:
$pattern = '/%%abc%%(.*?)%%xyz%%/';
$replacements = array('r1', 'r2', 'r3', 'r4');
$callback = function($matches) use ($replacements) {
    return $replacements[mapSubstringToInteger($matches[1])];
};

preg_replace_callback($pattern, $callback, $input);

Upvotes: 7

nickb
nickb

Reputation: 59699

Use preg_replace_callback(), like this:

preg_replace_callback( '#%%abc%%(.*?)%%xyz%%#', function( $match) {
    // Do some logic (with $match) to determine what to replace it with
    return 'replacement';
}, $master_string);

Upvotes: 1

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