No Call by reference in C?

pass by reference in c
call by value and call by reference in c
call by reference swap program in c
call by reference in c++
call by reference in java
call by value in c
call by address in c
call by value and call by reference in c++

I know, the title is a little bit odd. Of course I know how to do call-by-reference in C. My problem is simple and the solution could be simple as well. I am currently going through some scripts of my university and they explicitly write "Call-By-Reference is NOT used in C".

Since I (think I) know how to do call by reference in C, i am a little bit confused and hope you can help me out.

Do I generally understand something wrong about the term Call-By-Reference? Or is the code below actually call-by reference

void test(int* p) {
    *p = 5;
}

int main(int argc, char *argv[]) {
    int i = 2;
    test(&i);
    printf("i = %i\n",i);
    end;
}

Another explanation would be that call-by-reference is bad practice. For example Java does not allow call by reference for non objects. But since C is nor object oriented it makes no sense to me (beside maybe with structs)

Or is the script actually wrong?

Thank you in advance!

There is no concept of variable reference in C, as there is in C++. What you show in your small example is simply a use of a pointer (or variable address). But you are passing a value (the address of the variable) not a reference (an alias of the variable name).

Function call by reference in C, C parameters are always passed by value rather than by reference. that function because it only has pass-by-value and has no pointers. There is no concept of "reference" on the machine level. On the machine level you have either values or pointers. The C compiler would always generate pointers. It's different with C++ where the compiler MAY generate pointer, or may copy the value, may keep things in registers.

Or is the script actually wrong?

There is nothing wrong in your code.

This call test(&i); actually is pass by pointer (not by reference). In C, there is no concept about reference. The & here is address-of operator, not a reference.

The concept pass-by-reference is only applicable in C++, which means to pass the object itself (instead of passing a copy of it). Even that, though, the call to test would be different: test(i); // pass-by-reference instead of test(&i); // pass-by-pointer.

Does C even have "pass by reference"?, C Programming - Function call by reference: In this method the addresses of actual arguments (or parameters) are passed to the formal parameters. C Call by Reference: Using pointers In this tutorial, you'll learn to pass addresses as arguments to the functions with the help of examples. This technique is known as call by reference.

"Call-By-Reference is NOT used in C"

This is a totally wrong statement.

Each programming language has its own terminology. And in C call by reference or pass by reference means pass indirectly through a pointer to an object.

This wrong statement arises when somebody is saying about C but is using the terminology of the definition of the term reference introduced in other languages.

From the C Standard (6.2.5 Types)

A pointer type may be derived from a function type or an object type, called the referenced type. A pointer type describes an object whose value provides a reference to an entity of the referenced type. A pointer type derived from the referenced type T is sometimes called ‘‘pointer to T’’. The construction of a pointer type from a referenced type is called ‘‘pointer type derivation’’. A pointer type is a complete object type.

So pass by reference in C means the above context when a referenced type is used to deal with a referenced object. It is not a normative term however it is used in C to specify this approach of passing objects to functions through pointers.

In your program

#include <stdio.h>

void test(int* p) {
    *p = 5;
}

int main(int argc, char *argv[]) {
    int i = 2;
    test(&i);
    printf("i = %i\n",i);
    end;
}

you are passing the object i by reference through the pointer expression &i. So this expression *p = 5; changes the referenced object that is the referenced object is passed by reference in the terminology of C.

Function call by reference in C Programming, In C programming, it is also possible to pass addresses as arguments to functions. To accept these addresses in the function definition, we can use pointers. I am confused about the meaning of "pass by reference" in C and C++. In C, there are no references. So I guess pass by reference means passing a pointer. But then why not call it pass by pointer?

Reference is a concept that is used in C++ but not in C. In C we ususally use pointers and designate it as an address when it is about manipulating a struct "by reference" in stead of using a "by value" argument passing mechanism. Your code is just fine. The problem with pointers usually happens in C when you start allocating memory for a variable. The question which arises afterward is what code is responsible to free the allocated memory block. By the way anytime you write a function using a ponter you should test if it is not null

    void test(int* p) {
        if(p != NULL) {
            *p = 5;
        }
    }

    int main(int argc, char *argv[]) {
        int i = 2;
        test(&i);
        printf("i = %i\n",i);
        // end; // this is not a C instruction
        exit(0);
    }

C Call by Reference (With Examples), Functions can be invoked in two ways: Call by Value or Call by Reference. the called function have no effect on the values of actual variables in the calling function. In C++, we can either use pointers or references to for pass by reference. C provides two ways of passing arguments to a function. Call by value or Pass by value. Call by reference. Let's start with Call by value. Call by Value # In this method a copy of each of the actual arguments is made first then these values are assigned to the corresponding formal arguments.

Difference between Call by Value and Call by Reference , Call by Value and Call by Reference in C with programming examples for parameters do not change by changing the formal parameters in call by value,� Tags for Swapping numbers using call by reference in C. c program to swap numbers using call by reference; call by reference example program; program-swap two numbers using call by reference; swapping of two numbers using call by reference in c; write a c program to swap two numbers using call by reference; program to swap two numbers using

Call by Value and Call by Reference in C, The major difference between call by value and call by reference in C is that in called function have no effect on the values of actual arguments in the calling� When we call a function by passing the addresses of actual parameters then this way of calling the function is known as call by reference. In call by reference, the operation performed on formal parameters, affects the value of actual parameters because all the operations performed on the value stored in the address of actual parameters.

Difference Between Call by Value and Reference in C, This means that the changes made by the called function have no effect on the values of actual arguments in the calling function. In the example� The call by reference method of passing arguments to a function copies the reference of an argument into the formal parameter. Inside the function, the reference is used to access the actual argument used in the call. This means that changes made to the parameter affect the passed argument. To pass

Comments
  • Possible duplicate of Passing by reference in C
  • C does only have pass by value, nothing else.
  • Your university is right.
  • When you pass a pointer to a function it's a copy of the pointer, so it's still pass by value.
  • "This is a totally wrong statement". We don't know the context of this quote. I assume the sentence is a comparison with C++ where there is a difference between pointer and reference, that does not exist in C
  • @GuillaumePetitjean You could say for example that in C there is no such entities as references as they are defined in C++ with their special meaning. But this a totally different phrase.
  • @GuillaumePetitjean The phrase in ant case is totally wrong without any context.