There are three ways to get first character of a string in PHP.
1: By using array index position $res = $currency_value[0]; where $currency_value is holding string.
2: By using built-in PHP function substr() i.e $res = substr($currency_value,0,1);
3: By using built-in PHP function mb_substr() i.e $res = mb_substr($currency_value,0,1)
mb_substr() function is used when programmer is dealing with multibyte UTF8 characters.
Find a video here in which it has been explained clearly that how you can
get first character of a string in PHP.