How to detect a string with specific pattern from a larger string?

Question

I have a long string from which I want to detect and replace with some other text. Suppose my text is 'my first name is @[[Rameez]] and second name is @[[Rami]]'. I want to detect @[[Rameez]] and replace with Rameez dynamically to all likewise strings.

Answer 1

Specific version

// Find Rameez specifically
$re = '/@\[\[(?<name>Rameez)\]\]/i'; // Use i flag if you to want a case insensitive search
$str = 'my first name is @[[Rameez]] and second name is @[[Rami]].\nDid I forget to mention that my name is @[[rameez]]?'; 

echo preg_replace($re, '$1', '**RAMEEZ** (specific)<br/>' . PHP_EOL);

Generic version

Regex

@\[\[(?<name>.+?)\]\]

Description

(?<name> .. ) represents here a named capturing group. See this answer for details.

Sample code

// Find any name enclosed by @[[ and ]].
$re = '/@\[\[(?<name>Rameez)\]\]/i'; // Use i flag if you to want a case insensitive search
$str = 'my first name is @[[Rameez]] and second name is @[[Rami]].\nDid I forget to mention that my name is @[[rameez]]?'; 

echo preg_replace($re, '$1', '**RAMEEZ** (generic)<br/>' . PHP_EOL);

DEMO

Answer 2

You could simply do:

preg_replace('/@\[\[(\w+)\]\]/', "$1", $string);

[ and ] need to be escaped because they have special meaning in a regex.
This will replace any string @[[whatever]] by whatever

Answer 3

You can create a regex pattern then user it to match, find and replace a given string. Here's example:

string input = "This is   text with   far  too   much   " + 
                     "whitespace.";
      string pattern = "\\s+";
      string replacement = " ";
      Regex rgx = new Regex(pattern);
      string result = rgx.Replace(input, replacement);

It's C# code but you can apply it to any language really. In your case you can substitute the pattern with something like string pattern = "@[[Rameez]]"; and then use different replacement: string replacement = "Rameez"; I hope that makes sense.