In C#, why can double.TryParse() parse numbers in scientific notation, but decimal.TryParse() cannot?

Question

Hi,

I know the difference between the double and decimal datatype in C#, but from a design POV, why can double.TryParse() parse numbers expressed in scientific notation, but decimal.TryParse() cannot by default?

Thanks

Answer 1

Hi @pmullhi , Welcome to Microsoft Q&A.

From a design POV, the reason why double.TryParse() in C# can parse numbers expressed in scientific notation, while decimal.TryParse() cannot by default, is primarily due to the intended use cases and the trade-offs associated with each data type.

Double is a floating-point data type that provides a wider range of values and a larger precision compared to the decimal data type. It is typically used for scientific calculations, engineering applications, or situations where the exact precision of the value is not critical.

On the other hand, decimal is a fixed-point data type that offers higher precision and is designed for financial and monetary calculations, where accuracy and rounding behavior are crucial. The decimal type avoids many of the rounding errors that can occur with floating-point arithmetic, making it suitable for financial calculations, currency operations, and other scenarios that require exact decimal representations.

The difference in behavior between double.TryParse() and decimal.TryParse() is a result of these different use cases and requirements. When parsing a string representation of a number, double.TryParse() is more lenient and flexible because it aims to handle a broader range of inputs, including scientific notation. It allows the parsing of numbers expressed in scientific notation like "1.23e-4" or "2.5E6".

In contrast, decimal.TryParse() is stricter by default because it emphasizes precise decimal representation and avoids potential loss of precision. It does not support scientific notation directly out-of-the-box, as it expects the input to have a more explicit decimal representation, such as "0.000123" or "2500000".

Best Regards,

Jiale

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