In C#.NET data types and memory representation, what is the storage size of the built-in Decimal (System.Decimal) value type? Choose the most accurate size in bytes.
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A4 byte
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B8 byte
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C16 byte
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D32 byte
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E64 byte
Answer
Correct Answer: 16 byte
Explanation
Introduction / Context:The Decimal (System.Decimal) type in C#.NET is a high-precision, base-10 numeric type designed for financial and monetary calculations where rounding errors from binary floating-point types (Single/Double) are unacceptable. Knowing its exact size helps developers reason about memory usage and precision trade-offs.
Given Data / Assumptions:
- The question asks specifically for the storage size (in bytes) of System.Decimal.
- No code execution is required; this is a factual recall about .NET's type system.
- Other options list common sizes for primitive types to act as distractors.
Concept / Approach:System.Decimal is implemented as a 128-bit (16-byte) structure. Internally, it stores a 96-bit integer (significand) plus scaling information and a sign, enabling exact decimal representation for many base-10 values. This contrasts with Single (4 bytes, 32-bit) and Double (8 bytes, 64-bit) that use binary floating-point representation.
Step-by-Step Solution:
Identify the correct memory size for Decimal in the .NET type system.Recall that Decimal is 128 bits total → 128 / 8 = 16 bytes.Match this with the provided choices.Verification / Alternative check:You can confirm by checking sizeof(decimal) in an unsafe context or by consulting official .NET documentation indicating Decimal is 128 bits.
Why Other Options Are Wrong:
- 4 byte and 8 byte correspond to Single and Double respectively, not Decimal.
- 32 byte and 64 byte greatly overstate Decimal's size.
Common Pitfalls:Confusing Decimal with Double due to both being used for real numbers. Decimal is significantly larger (16 bytes) and optimized for base-10 precision, not scientific computation speed.
Final Answer:16 byte