c++ only allow certain parameters to placed in argv[1]
Im trying to write some code that will only let one of four letters be entered in the argv[1] parameter. if it is another character the letter q should come up.

so ive written

`#include <iostream>`

`#include <cstdlib>`

`char D, A , R, B;`

    if(argv[1] != D||A||R||B)
   {
  `cout << "Q" << endl;` 
    `return(0);`
    }

can anyone please help me 

c++ only allow certain parameters to placed in argv[1]
===

Im trying to write some code that will only let one of four letters be entered in the argv[1] parameter. if it is another character the letter q should come up.

so ive written

`#include <iostream>`

`#include <cstdlib>`

`char D, A , R, B;`

    if(argv[1] != D||A||R||B)
   {
  `cout << "Q" << endl;` 
    `return(0);`
    }

can anyone please help me 
