Store an int in a char array?

Question

I want to store a 4-byte int in a char array... such that the first 4 locations of the char array are the 4 bytes of the int.

Then, I want to pull the int back out o

Answer 1

Note: Accessing a union through an element that wasn't the last one assigned to is undefined behavior. (assuming a platform where characters are 8bits and ints are 4 bytes) A bit mask of 0xFF will mask off one character so

char arr[4];
int a = 5;

arr[3] = a & 0xff;
arr[2] = (a & 0xff00) >>8;
arr[1] = (a & 0xff0000) >>16;
arr[0] = (a & 0xff000000)>>24;

would make arr[0] hold the most significant byte and arr[3] hold the least.

edit:Just so you understand the trick & is bit wise 'and' where as && is logical 'and'. Thanks to the comments about the forgotten shift.