Why use argc and argv ??

Answer 1

tq

Answer 2

argc4 
argv[0]gcc 
argv[1]-o 
argv[2]myprog 
argv[3]myprog.c

As you can see, the first argument (argv[0]) is the name by which the program was called, in this case gcc. Thus, there will always be at least one argument to a program, and argc will always be at least 1.