Question

If the numerical value of a 2-byte unsigned integer on a little endian computer is 255 more than that on a big endian computer, which of the following choices represent(s) the unsigned integer on a little endian computer?

• A. 0x6665
• B. 0x0001
• C. 0x4243
• D. 0x0100

Hint:

For 2-byte numbers, an endian difference of 255 occurs exactly when the two bytes differ by 1.

Answer 1

The Correct Option is A, D

To solve this problem, we need to understand how numbers are represented differently in little endian and big endian formats. In a little endian system, the least significant byte (LSB) is stored first. In a big endian system, the most significant byte (MSB) is stored first. Given that the numerical value on a little endian computer is 255 more than that on a big endian computer, let's explore the options to determine the correct answer.

1. Analyze the differences in endianness:
   • If a number is represented as 0xABCD in big endian, its little endian equivalent would be 0xCDAB.
2. Identify possible candidates: We need a case where \text{Little Endian Value} = \text{Big Endian Value} + 255.
3. Verification of options:
   • Option 1: 0x6665 - Little endian as 0x6566, Big endian as 0x6665.
   • Convert these hexadecimal values to decimal:
   • 0x6566 = 25958, 0x6665 = 26213. The difference is indeed 255.
4. • Option 4: 0x0100 - Little endian as 0x0001, Big endian as 0x0100.
   • Convert these hexadecimal values to decimal:
   • 0x0001 = 1, 0x0100 = 256. Here, also the difference is 255.

Both options meet the condition, hence the correct choices are 0x6665 and 0x0100.