C const pointer

void main()
{
const int * a;
*a = 5;
}

gcc error : assignment of read only location.

so, how to assign to *a, without using another variable? and what could be a use of a declaration like above?

Ans : 

void main()
{
const int * a;
*a = 5;
}

Ans 2 : 

hi,
refer here,
http://publications.gbdirect.co.uk/c_book/chapter8/const_and_volatile.html