Comparing char arrays

Hi was wondering if I am comparing 2 char arrays of the same size, can i use memcmp?

Or is there a better way of comparing?

If that's the type of comparison you need, it's fine. Did you try it? Is that the type of comparison you need?

Quote:

---

Originally Posted by Edelweiss

Hi was wondering if I am comparing 2 char arrays of the same size, can i use memcmp?

Or is there a better way of comparing?

---

It depends. strcmp is a lexicographical comparison which means the function understands 'a' is less than 'b' because 'a' comes before 'b' and so forth. memcmp is not.

Quote:

---

Originally Posted by whiteflags

It depends. strcmp is...

---

...for strings.


Quzah.

lol. but if i want to use memcmp between an uint8_t array of size 2 and a uint16_t variable, does it still work? since its comparing the memory at the address right?

Code:

---

union moarcheating
{
    uint8_t a[2];
    uint16_t b;
} a, b;

a.a[0] = 0xAA;
a.a[1] = 0xBB;

b.b = 0xAABB; /* assuming your endian is correct */

if( b.b == a.b )
    printf( "omg hax\n" );

---

Quzah.

But if your uint16 contains 0x1234 and your uint8 array contains [ 0x12, 0x34 ] then it is down to the endian of your machine as to whether they compare equal or not (using memcmp)

You're better off with
if ( (var & 0xff) == array[0] && ((var>>8)&0xff) == array[1] )