How does the C language differentiate whether the current system is 32-bit or 64-bit?

32-bit and 64-bit refers to the number of operating system bits, mapped to the C language, the most intuitive is the pointer type occupies the number of bytes.

1 32-bit system:

The address occupies 32 bits, so the pointer type also accounts for 32 bits, or 4 bytes.

2 64-bit system:

The address occupies 64 bits, so the pointer type also accounts for 64 bits, or 8 bytes.

Therefore, you only need to judge the sizeof value of any one pointer, you can get the number of in place.

Such as

int main ()

{

int bits= sizeof (char *);

if (bits = = 4) printf ("32-bit \ n");

else if (bits = = 8) printf ("64-bit \ n");

else printf ("Others, bits =%d\n", bits);

}

How does the C language differentiate whether the current system is 32-bit or 64-bit?