In this PHP tutorial, you shall learn how to convert a given string to lowercase using strtolower() function, with example programs.
PHP – Convert string to lowercase
To convert a string to lowercase in PHP, use strtolower() function. Call strtolower()and pass the given string as argument.
Syntax
The syntax to convert the string str to lowercase using strtolower() function is
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strtolower($str);
The function returns a string value with all the characters in the given string converted to lowercase.
Examples
1. Convert string to lowercase
In this example, we will take a string str that has some uppercase characters. We convert this string to lowercase and print it.
PHP Program
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<?php
$str = 'Hello World';
$output = strtolower($str);
echo $output;
?>
Output

Conclusion
In this PHP Tutorial, we learned how to convert a string to lowercase, using strtolower() function.
