Converting an int into a 4 byte char array (C)

Question

Hey, I\'m looking to convert a int that is inputed by the user into 4 bytes, that I am assigning to a character array. How can this be done?

Example:

Convert

Answer 1

int a = 1;
char * c = (char*)(&a); //In C++ should be intermediate cst to void*

Answer 2

The issue with the conversion (the reason it's giving you a ffffff at the end) is because your hex integer (that you are using the & binary operator with) is interpreted as being signed. Cast it to an unsigned integer, and you'll be fine.

Answer 3

You can simply use memcpy as follows:

unsigned int value = 255;
char bytes[4] = {0, 0, 0, 0};
memcpy(bytes, &value, 4);

Answer 4

Do you want to address the individual bytes of a 32-bit int? One possible method is a union:

union
{
    unsigned int integer;
    unsigned char byte[4];
} foo;

int main()
{
    foo.integer = 123456789;
    printf("%u %u %u %u\n", foo.byte[3], foo.byte[2], foo.byte[1], foo.byte[0]);
}

Note: corrected the printf to reflect unsigned values.