PHP str_replace Function | Complete Guide

In this tutorial, we learn PHP str_replace Function with help of multiple types of examples. How we can use the PHP str_replace function at the time of development.

Here are some important points that we will discuss in this tutorial,

Example of PHP string replace function.
How to use PHP str_replace with arrays.
PHP str_replace to replace multiple strings or values.
Replace using PHP str_replace case insensitive.

PHP str_replace and str_ireplace Function | Complete Guide

Introduction to PHP string replace Function

PHP string replace function is used to replace specified characters with other characters from the string.

The function works followed by these rules,

PHP string replace function check character case (case sensitive).
If the string is searched in an array then it also returns an array.
In array search and replace, PHP replace function checks all the array elements.

Syntax

str_replace(find,replace,string,count)

1	str_replace(find,replace,string,count)

Return Value: Returns a string or an array with the replaced values

Parameter Values

Parameter	Description
find	Specifies the value to find (Required)
replace	Specifies the value to replace the value in find (Required)
string	Specifies the string to be searched (Required)
count	A variable that counts the number of replacements (Optional)

Example of PHP str_replace Function

<?php
$str = "Example of PHP string replace function.";
$modifyString = str_replace("Example","Best example", $str);
echo $modifyString;
?>

<?php

$str = "Example of PHP string replace function.";

$modifyString = str_replace("Example","Best example", $str);

echo $modifyString;

Output: Best example of PHP string replace function.

PHP str_replace Function With an Arrays Code Example

<?php
	$find = array("Hello","world");
	$replace = array("B");
	$arr = array("Hello","world","!");
	print_r(str_replace($find,$replace,$arr));

?>

<?php

$find = array("Hello","world");

$replace = array("B");

$arr = array("Hello","world","!");

print_r(str_replace($find,$replace,$arr));

Output:

PHP str_replace to Replace Multiple Values or String Code Example

<?php
	// Provides: You should eat pizza, beer, and ice cream every day
	$phrase  = "You should eat fruits, vegetables, and fiber every day.";
	$healthy = ["fruits", "vegetables", "fiber"];
	$yummy   = ["pizza", "beer", "ice cream"];

	$newPhrase = str_replace($healthy, $yummy, $phrase);
	echo $newPhrase;
?>

<?php

// Provides: You should eat pizza, beer, and ice cream every day

$phrase = "You should eat fruits, vegetables, and fiber every day.";

$healthy = ["fruits", "vegetables", "fiber"];

$yummy = ["pizza", "beer", "ice cream"];

$newPhrase = str_replace($healthy, $yummy, $phrase);

echo $newPhrase;

Code Highlights:

In this example, there is a string statement where we do apply the find and replace function to replace multiple values or strings.

Now we create two arrays that we place into the str_replace() function and then replace one array element with another array element.

Output:

PHP str_replace multiple — PHP string replace for replace multiple values

Replace String Using PHP str_ireplace With Case Insensitive

To find and replace without checking character cases we can use PHP str_ireplace function.

<?php
	$arr = array("blue","red","green","yellow");
	
	// This function is case-insensitive
	$newArray = str_ireplace("RED","pink",$arr,$i);
	print_r($newArray);
?>

<?php

$arr = array("blue","red","green","yellow");

// This function is case-insensitive

$newArray = str_ireplace("RED","pink",$arr,$i);

print_r($newArray);

Output: