You can't pass an enum as an argument to a function. An enum in C isn't an object, it's a type. All you can do is pass a variable that is of the particular enum's type.
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if you have a function or a method that takes Object as a parameter, you can call that function or method and pass an Object as follows: Let's say you have a class that extends Object and a function as follows public class A extends Object { ..... } void function ( A arg ){ ..... } To call this function, you need an instance of the class A A objectInstance = new A(); function(objectInstance); The next line shows how to pass an instance of the class A to the function.
When you pass by value, the function's parameter is assigned the value of the argument that was passed. When you pass by reference, the function's reference parameter is assigned the address of the argument. In other words, pass by value copies the value, pass by reference passes the variable itself.Pass by reference is always the preferred method of passing arguments to functions when those arguments are complex objects. If the argument is a primitive data type then the cost in copying the value is minimal, but copying a complex object is expensive in terms of performance and memory consumption. If the function parameter is declare constant, you can be assured the object's immutable members will not be affected by the function. If it is non-constant and you do not wish your object to be altered, you can either copy the object and pass the copy, or pass the object by value if the function is overloaded to cater for this eventuality (good code will provide both options).
When we invoke a function, we pass the actual arguments in the same order specified by the function's formal arguments, thus it is the relative position that determines how they are matched. Note that actual parameter names are within the scope of the calling code while formal parameter names are scoped to the function in which they are declared. The calling code has no access to the formal argument names, and the function may or may not have access to the actual argument names. Python uses the pass-by-object paradigm: if the object being passed is immutable, then it is passed by value (the formal parameter is assigned a copy of the object's value), otherwise it is passed by reference (in which case the formal argument becomes an alternative name for the actual argument).
Strictly speaking, no. All arguments in C are passed by value. However, when the argument being passed is a memory address, although the address itself is passed by value, we're effectively passing the object that resides at that address -- by reference. Thus when a function's formal argument is a pointer variable (of any type), then it can be taken as read that the function is using the pass by reference semantic rather than the pass by value semantic. Nevertheless, it is important to keep in mind that the formal argument is assigned a copy of the actual argument and is therefore being passed by value.
When you pass an object to a function you are not actually passing the object, you are only passing the object's value. This is what is meant by the term pass by value.When passing a value to a function there are actually two objects involved in the exchange: the actual argument (the object that is being passed) and the formal argument (the object used by the function). When we call a function that accepts one or more arguments (also known as parameters), the value of the actual argument is assigned to the corresponding formal argument. Thus the formal argument is a copy of the actual argument and any changes made to the formal argument will have no effect upon the actual argument.When the formal argument is a pointer, however, the value we pass is a memory address. The actual argument can either be a pointer of the same type or we can take the address of an object of the same type using the address-of operator and pass that. Either way, the value we pass is a memory address. We call this pass by reference even though the address is actually being passed by value. Passing by reference means that the formal argument and the actual argument both refer to the same object and offers an efficient means of passing large objects that are too expensive to copy. This includes most structures and unions and all arrays. Note that arrays implicitly decay to pointers and therefore cannot be passed by value. Structures and unions can be passed by value, but if they are larger than a pointer (in bytes) passing by reference is more efficient.There are four different ways to declare a formal argument as a pointer:mutable pointer to mutable typemutable pointer to constant typeconstant pointer to mutable typeconstant pointer to constant typeIdeally, functions should declare formal pointer arguments using methods 2 or 4. Both point to constant types so this gives the caller an assurance that the function has no side effects upon the object being passed by reference. Functions that use methods 1 or 3 should be regarded as having side-effects upon the object being referred to. This can be desirable for efficiency reasons, however returning values via arguments (also known as output parameters) should be avoided whenever possible.Note that it makes no difference if the formal pointer argument is mutable or constant because the formal and actual arguments are still separate objects. Constant formal arguments are only of relevance to the function designer, they are of no importance to the caller. This is true of all values passed to functions whether the value is a memory address or not. What is important to the caller of a by reference function is whether or not the object being pointed at is declared constant or not.