In C, what is the typical form of a function declaration when implementing call by value?

In C, the typical form of a function declaration when implementing call by value is as follows:

return_type function_name(data_type variable_name)
{
    // function body
}

Here's a step-by-step breakdown:

1. return_type: This is the data type of the value that the function will return. It could be int, float, char, void, etc.

2. function_name: This is the name of the function. It can be any valid identifier in C.

3. data_type variable_name: This is the parameter that the function takes. The data_type is the type of the parameter, and variable_name is the name of the parameter. In call by value, the function receives a copy of the parameter, not the original variable itself.

4. {...}: This is the body of the function, where the actual code goes.

Here's an example:

int add(int a, int b)
{
    return a + b;
}

In this example, int is the return type, add is the function name, and int a, int b are the parameters. The function adds a and b and returns the result.