Difference between char *argv[] and char **argv for the second argument to main() [duplicate]

Answer 1

[EDIT] Using GCC at the time of the comment probably GCC 7.2

declaring an array like this

char array[]

makes it const which means that you CAN'T have the following code

char array[] = "hello";
array = "hey";

even though the second string is smaller and should fit you get this error

error: array type 'char [6]' is not assignable

if you have **argv you can write

main(int argc, char **argv)
{
    char **other_array;
    /*
     * do stuff with other_array
     */
    argv = other_array;
}

if you have *argv[] then

main(int argc, char *argv[])
{
    char **other_array;
    /*
     * do stuff with other_array
     */
    argv = other_array;
}

gives you this warning

warning: assigning to 'const char **' from 'char **' discards qualifiers in nested pointer types

so it is technically a small optimisation as if you had written const