What is the Function Parameter Evaluation Order in C and C ?

Function Parameter Evaluation Order in C and C

In computer programming, function parameters are evaluated to provide arguments to the function being called. The order in which these parameters are evaluated can impact the execution of the function. Let's examine the evaluation order for C and C functions.

C

According to the C99 standard, the order of evaluation for function parameters is unspecified. However, there is a sequence point before the actual function call. This means that all parameter evaluations are complete before the function is invoked.

C

Similar to C, the C standard does not mandate a specific evaluation order for function parameters. The order is left unspecified. However, it states that side effects of parameter expressions occur before the function is entered.

Implementation Details

While the language standards do not prescribe how function parameters are passed, most architectures use the hardware stack. However, it is essential to note that this is not a requirement from the language perspective.

Conclusion

The evaluation order for function parameters is unspecified in both C and C . This means that the programmer cannot rely on a particular order. Furthermore, the implementation details of parameter passing are left to the compiler and platform. Understanding the underlying language rules and implementation details is crucial for effective function design and optimization.

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