char* text = (argc == 3) ? argv[2] : argv[1];

Question

Could someone explain me what the line in the title actually does?

Am I correct

if argc is 3
    char* text is argv[2]
else
    char* text is argv[1]

?

If so, how do the operators work in this line?

Answer 1

Yes, you are correct.

char* text = (argc == 3) ? argv[2] : argv[1];

actually means

char* text = ((argc == 3) ? argv[2] : argv[1]);

i.e. assign some value to char *text with the help of Ternary Operator.

Ternary operators work as

some_condition ? execute_this_if_true : execute_this_if_false ;

Here, firstly, argc == 3 is evaluated. Depending on whether true or false, the next statement is executed. But the whole is used with an assignment operator(=), so the value argv[2] is assigned if test evaluates to true(argv[3] if test evaluates to false).

Same things can be done with return statements. Say, You want to design a function that returns remainder when a number is divided by 2, then you can use ternary operator as follows :

int foo(int n)
{
      return (n%2 == 1) ? 1 : 0 ;
}