PHP String Replace

Ever wanted to change “Hello World” to “Hello Universe” with a snap? In PHP, you can **easily replace words or characters** inside a string using str_replace(), preg_replace(), and other functions. Let’s dive in! 🚀

🔹 Basic String Replacement with str_replace()

The str_replace() function replaces all occurrences of a word or character inside a string.

<?php
$text = "I love cats! Cats are awesome!";
$search = "cats";
$replace = "dogs";

$new_text = str_replace($search, $replace, $text);

echo $new_text;
?>

Try It Now

Output: I love dogs! Dogs are awesome!

Note: str_replace() is case-sensitive, so “Cats” (uppercase) won’t be replaced unless specified.

🔹 Replacing Multiple Words at Once

You can replace multiple words by passing arrays as parameters.

<?php
$text = "Roses are red, violets are blue.";
$search = array("red", "blue");
$replace = array("green", "yellow");

$new_text = str_replace($search, $replace, $text);

echo $new_text;
?>

Try It Now

Output: Roses are green, violets are yellow.

🔹 Case-Insensitive Replacement with str_ireplace()

If you want to replace text regardless of case, use str_ireplace().

<?php
$text = "I love PHP, php is great!";
$search = "php";
$replace = "JavaScript";

$new_text = str_ireplace($search, $replace, $text);

echo $new_text;
?>

Try It Now

Output: I love JavaScript, JavaScript is great!

Difference: Unlike str_replace(), str_ireplace() doesn’t care if “php” is lowercase or uppercase. It replaces all!

🔹 Advanced Replacements with preg_replace()

Need to replace words **with patterns**? Use preg_replace() (supports regex). Let’s replace all digits with “X”.

<?php
$text = "My phone number is 123-456-7890.";
$pattern = "/\d/"; // \d matches any digit
$replace = "X";

$new_text = preg_replace($pattern, $replace, $text);

echo $new_text;
?>

Try It Now

Output: My phone number is XXX-XXX-XXXX.

🎯 Key Takeaways

  • str_replace() → Replaces text (case-sensitive).
  • str_ireplace() → Replaces text (case-insensitive).
  • preg_replace() → Uses regex patterns for advanced replacements.

📝 Practice Time!

Try replacing random words! Maybe change “Monday” to “Friday” and make the week shorter! 🤣