The **`strtolower` method** can convert all the alphabetical characters of the string to lowercase characters and returns the modified string as a *new string*.

# 
#  Syntax 

---
    strtolower(string $string): string
---

# 
## Returns

This method returns a new string. The string passed as the argument remained unchanged.

##
## Code

<?php 
    $str = "TEST_123";
    $str_lower = strtolower($str);
    echo "The lowercase value of ". $str. " is ". $str_lower. "\n";

    $str = "EDUcativE";
    $str_lower = strtolower($str);
    echo "The lowercase value of ". $str. " is ". $str_lower. "\n";
?>

# 
#  Explanation

In the code above, we have used the `strtolower` method and converted the strings `TEST_123` and `EDUcativE` to lowercase strings. The `strtolower` will convert.

##
## Output

---
```
"TEST_123" to "test_123"
"EDUcativE" to "educative"
```
---
> Refer [here](https://www.php.net/manual/en/function.strtolower.php) for more details.

What is the strtolower method in PHP?

Converts alphabetic characters of a string to lowercase and returns a new modified string.