(PHP 7 >= 7.2.0, PHP 8)
sodium_add — Add large numbers
&$string1, string $string2): void
This adds the parameter string2 to string1, overwriting
the value stored in string1. This function assumes both parameters are binary
strings that represent unsigned integers in little-endian byte order.
string1String representing an arbitrary-length unsigned integer in little-endian byte order. This parameter is passed by reference and will hold the sum of the two parameters.
string2String representing an arbitrary-length unsigned integer in little-endian byte order.
No value is returned.