strtolower(): to change upper case chars to lower case
$val=strtolower($input_sting);
We can use strtolower() function in PHP to change all the alphabetic characters to lowercase. This simple function takes one string as input and changes the characters present inside to lower case.
Here is an example code.
$my_str="Hello welcome to plus2net.com";
$my_str=strtolower($my_str);
echo $my_str;