PHP String Replace by using str_replace case sensitive function

$str='Hello to plus2net.com';
$search='Hello';
$replace='Welcome';
echo str_replace($search,$replace,$str);

Output is here

Welcome to plus2net.com

Syntax

str_replace(search,replace,main_string,count);

search:

Required: String to be searched for matching, can be an array

replace:

Required: String to be replaced if found using search string, can be an array

main_string:

Required : String on which search and replace to be applied, can be an array

count:

Optional: Stores the number of replacements performed.

Output is a string or array after performing search and replace over the input string

To replace a part of the string with another string we will use str_replace function in PHP. This function will replace all the occurrence of the string we target and will replace with the string we supply.
Here is an example.


<?Php
$string="This is an example on how html is used in 
developing user-friendly web sites. By using HTML  we can
 control the content of a page";

echo $string;
echo "<br><br>";
$string=str_replace("html","PHP",$string);

echo "<b>After replace</b> <br><br>$string";

?>

If you run the above code your will see result like this


This is an example on how html is used in developing user-friendly web sites. By
using HTML we can control the content of a page

After replace


This is an example on how PHP is used in developing user-friendly web sites. By
using HTML we can control the content of a page

Here you can see the text html is replace by PHP but HTML is not replaced.
So str_replace() is a case sensitive string replacing function. We can use str_ireplace() to get case insensitive string replacement

Find & Replace

We can create an array of search strings and an array or replace strings. These two array we can apply to search and replace words from the content. The matching words will be replace by matching strings from replace array. Original String

Welcome to Plus2net.com to learn PHP, MYSQL, HTML, jquery and many more.

After replacement

Welcome to plus2net.com to learn php, MySQL, html, JQuery and many more.

Here is the code

$contents="Welcome to Plus2net.com to learn PHP, MYSQL, HTML , jquery and many more.";
echo "Original String $contents";
$search=array("Plus2net.com","PHP","jquery","HTML","MYSQL");
$replace=array("plus2net.com","php","JQuery","html","MySQL");
$contents=str_replace($search,$replace,$contents);
echo "After replacement $contents";

Highlighting the changes.

Replace the replace array with additional tags to highlight the replaced string.

$replace=array("plus2net.com","php","<span style='background-color: #FFFF00'>JQuery</span>","html","MySQL");

Using optional parameter count

We can store number of search and replacement carried out using str_replace function.

$str='Raju is a good boy and he has many good habits.';
$search='good';
$replace='bad';
echo str_replace($search, $replace, $str,$count);
echo "<br>Number of replacements = $count <br>";

Output is here

Raju is a bad boy and he has many bad habits.
Number of replacements = 2

Read how search & replace is used to change content of a page
String Functions Case in-sensitive string replace

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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Case sensitive String Replace

Find & Replace

Highlighting the changes.

Using optional parameter count

Subhendu Mohapatra