The example is dumb because the number of elements in suffixes is fixed. next is a pointer to something that has a pointer, to something that has a pointer, ad infinitum.
C program #include Ī circular list that uses infinite indirection #include Įach element in suffixes has one suffix (two characters plus the terminating NUL character) and a pointer to the next element. It shows that when p points to i, *p can appear wherever i can. If p is a pointer to a constant, *p is not a modifiable lvalue it can’t go on the left side of an assignment. *p is an lvalue like a variable, it can go on the left side of an assignment operator, to change the value. (Some people would read it as “Go indirect on p.”)
*p means “apply the indirection operator to p” its value is the value of the object that p points to. If p is a pointer, the value of p is the address of the object. If you have a pointer to a variable, or any other object in memory, you have an indirect reference to its value. Now you know what pointers are, you will learn how pointers are related to arrays in the next tutorial.If you declare a variable, its name is a direct reference to its value. To avoid this confusion, we can use the statement like this: int* p = &c In both cases, we are creating a pointer p (not *p) and assigning &c to it. Why didn't we get an error when using int *p = &c ? Here's an example of pointer syntax beginners often find confusing.
Suppose, you want pointer pc to point to the address of c. This change the value at the memory location pointed by the pointer pc to 2.Ĭommon mistakes when working with pointers This assigns the address of variable c to the pointer pc. That is, 22 is stored in the memory location of variable c. And, variable c has an address but contains random garbage value. Since pc and c are not initialized at initially, pointer pc points to either no address or a random address. Here, a pointer pc and a normal variable c, both of type int, is created. Printf("Content of pointer pc: %d\n\n", *pc) // 11 Printf("Content of pointer pc: %d\n\n", *pc) // 22 Printf("Address of pointer pc: %p\n", pc) Then, the address of d is assigned to the pc pointer using pc = &d. Initially, the address of c is assigned to the pc pointer using pc = &c. To get the value stored in that address, we used *pc. Here, the address of c is assigned to the pc pointer. To get the value of the thing pointed by the pointers, we use the * operator. And, the address of c is assigned to the pc pointer. Here, we have declared a pointer p1 and a normal variable p2. Let's take another example of declaring pointers. You can also declare pointers in these ways.
Here, we have declared a pointer p of int type.
Pointers (pointer variables) are special variables that are used to store addresses rather than values. Note: You will probably get a different address when you run the above code. Here, the value entered by the user is stored in the address of var variable. We have used address numerous times while using the scanf() function. If you have a variable var in your program, &var will give you its address in the memory. Before we learn pointers, let's learn about addresses in C programming. Pointers are powerful features of C and C++ programming.