c - How to Generate bit mask for a number from the number itself? -

is there way can generate bit mask of number without changing number itself?

i new programming , have seen hard-coded bit-masks only.

can operations on number generate bitmask, number (i.e.: dynamically generated mask, depending value of number)

thanks.

why not? use number mask:

//returns true if bit n 1 , false otherwise bool get(int index, int mask) {     return (mask >> index) & 1; }