why padding is not happening in this case?

Question

As per my knowledge, By default 4-byte alignment will be done. say

typedef struct
{
     int data7;  
     unsigned char data8;
     //3 -bytes will be added         


        

Answer 1

data7 is a 4-byte item, so the compiler will normally attempt to align it to an address that's a multiple of 4.

data1 is a one-byte item, so the compiler won't try to align it to any particular boundary (i.e., there would be no real gain from doing so).