Experiment 4: Differing Numbers of Parameters and Arguments

In this experiment, we will answer two different questions.

Question 4a: What happens if the number of arguments does not match the number of parameters in the function prototype?

Hypothesis: Using your experience and intuition, construct a hypothesis (a statement that answers the question) in the space below.



The Experiment: In the prototype of function Change(), add a fourth parameter so that the number of parameters differs from the number of arguments.

   void Change(int, int, int, int)

Observation: Translate your source program. What is displayed ?





Conclusions:

When the number of parameters in the prototype is different from the number of arguments in the function call, a compilation error results.

Restore the prototype to its original form, and then continue.

Question 4b: What happens if the number of arguments does not match the number of parameters in the function definition?

Hypothesis: Using your experience and intuition, construct a hypothesis (a statement that answers the question) in the space below.



The Experiment: In the definition of function Change(), add a fourth parameter so that the number of parameters differs from the number of arguments.

void Change(int param1, int param2, int param3, int param4)
{
 	param1 = 1;
 	param2 = 2;
 	param3 = 3;
}

Observation: Translate your source program. What is displayed? How does it differ from what was displayed when we modified the prototype?





Conclusions:

When the number of parameters in the prototype is different from the number of arguments in the function call, a linking error results. The compiler checks the validity of a function call using the prototype, and so the program compiles correctly. However the program fails to link because the linker cannot find a function definition that matches the prototype.

Restore the definition to its original form and then continue.

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