A float occupies 4 bytes. If the hexadecimal values of these 4 bytes are A, B, C, and D, in what order are they stored in memory? Consider hardware endianness when determining byte order.
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AABCD
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BDCBA
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C0xABCD
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DDepends on big endian or little endian architecture
Answer
Correct Answer: Depends on big endian or little endian architecture
Explanation
Introduction:Byte order in memory is determined by the machine's endianness, not by the C type (float) itself. The question evaluates awareness of big-endian versus little-endian storage conventions.
Given Data / Assumptions:
- Type size: 4 bytes
- Per-byte hex values labeled A, B, C, D
- Unknown CPU endianness
Concept / Approach:Big-endian systems store the most significant byte at the lowest address (ABCD), while little-endian systems store the least significant byte first (DCBA) for a 4-byte value. C does not mandate endianness; it is implementation- and hardware-defined.
Step-by-Step Solution:1) Identify that endianness is a property of the platform.2) Recognize that both ABCD and DCBA are possible depending on the machine.3) Therefore, without specifying architecture, the only correct general answer is: it depends.
Verification / Alternative check:On a system, inspect memory through a byte pointer cast or use utilities to print addresses and byte contents of a known value to observe actual order.
Why Other Options Are Wrong:ABCD: assumes big-endian only.DCBA: assumes little-endian only.0xABCD: represents a halfword-style literal; not a 4-byte byte-order description.
Common Pitfalls:Assuming a universal order based on experience with one architecture (e.g., x86 little-endian). Portable code should not depend on a particular endianness unless documented.
Final Answer:Depends on big endian or little endian architecture