Invalid Function Declaration in C

The correct answer is option 'B', which is not a valid function declaration in C. Let's understand why this option is invalid and explore the valid function declarations.

Invalid Function Declaration

b) int myFunction(int a, int ;b)

In this option, there is a semicolon (;) placed incorrectly after the second parameter declaration. In C language, semicolons are used to terminate statements, not within parameter declarations. Therefore, this option is not a valid function declaration.

Valid Function Declarations

a) int myFunction(int a, int b) {}

This option is a valid function declaration. It declares a function named myFunction that takes two integer parameters (a and b) and returns an integer value. The function body is enclosed within curly braces {}.

c) int myFunction();

This option is also a valid function declaration. It declares a function named myFunction that takes no parameters and returns an integer value. The empty parentheses () indicate that the function does not have any parameters.

d) void myFunction(int a, int b);

This option is a valid function declaration. It declares a function named myFunction that takes two integer parameters (a and b) and does not return any value. The keyword "void" is used to indicate that the function does not return a value.

In C, function declarations follow the syntax: return_type function_name(parameter_list);

- The return_type specifies the data type of the value returned by the function.
- The function_name is the name given to the function.
- The parameter_list is a comma-separated list of parameters (data type followed by parameter name) enclosed in parentheses.

Conclusion

The invalid function declaration is option 'B' because it contains a semicolon (;) after the second parameter declaration. The correct function declarations include options 'A', 'C', and 'D'. These options demonstrate the correct syntax for declaring functions in C, including specifying the return type, function name, and parameter list.