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Can a pointer be indexed like array?


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Answered 2013-04-29 14:51:02

A pointer is normally considered an atomic data type. Therefore, a pointer cannot "be indexed like an array" in that it is not possible to access portions of a pointer through an index.

However, a pointer can point to data which can be accessed through pointer operations as well as through index operations. Further, multiple pointers can be arranged in an array of pointers, and each individual pointer within that array of pointers can be reached through its array index.

Example 1: an array of pointers

const char* const array_of_pointers[] = {

"Hello, World", "Hello, Venus", "Hello, Mars"

};

In this example, each of array_of_pointers[0], array_of_pointers[1] or array_of_pointers[2] evaluates to one pointer, selected with the array index 0..2.

Example 2: access to data through pointer using an array-style index

void example(char* const text) {

*text = 'a'; // set first character pointed to to 'a'

*(text+1) = 'b'; // second char becomes 'b'

// the following are equivalent to the above, but use index notation:

text[0] = 'a';

text[1] = 'b'; }

Key to example 2 is the declaration of the pointer as a constant pointer.

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There is no such thing as an "array to pointer." What you might be asking is "array of pointers." An array of pointers is just that, an array in which the variables are pointers. In C this would be an array of pointer variables that are each 4 bytes in size. It is declared like this: int *pointers[3]; A pointer to an array is a pointer that points to the whole array. For example, in C if you have int numbers[5][10]; int (*pointerToArray)[10] = numbers + 2; pointerToArray points to the third element of numbers, which is itself an array.


Why can't we increment an array like a pointer?

once we initialize the array variable, the pointer points base address only & it's fixed and constant pointer


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Can an array be accessed through a pointer?

yes.. an array can be accessed through pointer


What is the difference between pointer and array?

Pointer holds an address Array holds values


What is a pointer in the array?

A pointer into an array of elements of type E is a pointer to a single element of type E:typedef ..... E;E array[123];E* const pointer = &array[18]; // points to the 19th element inside 'array'An array of pointers is an array whose elements are pointers:typedef .... E;E* array[123];E** const pointer = &array[18]; // points to the 19th pointer within 'array'Referencing the name of the array variable without use of the index operator itself is a constant pointer to its first element. Therefore, the following if-clause is always true:typedef .... E;E array[123];if (array &array[N]) { // ALWAYS true ...}


What is the easiest way to pass arrays as argument in c?

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When does an array behave a pointer?

An array behaves like a pointer when you use its name in an expression without the brackets.int a[10]; /* a array of 10 ints */int *b = a; /* a reference to a as a pointer, making b like a */int c = *(a+3); /* a reference to a[3] using pointer semantics */myfunc(a); /* pass a's address, a pointer to myfunc */Note very carefully that, while an array name and a pointer can almost always be interchanged in context, the are not the same, in that a pointer is an l-value, such as b, above, and can be assigned, whereas a is an r-value and can only be referenced, such as in the same statement, the second statement. Also, an array name does not take up memory, while a pointer does.


What is a pointer to pointers?

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How do you return an array from function?

By returning a pointer to the first element of the array.


Relation between array and pointer?

Array name is a static pointer to the array.Meaning of static here is that we can not modify the pointer (array name) value to any other value. Array name is the base address of the array in memory. for example if we have array a[5] of float starting at address 1000 in memory then a tells us the base address of array or address of a[0] i.e. 1000. a+1 tells the address of element a[1] and so on. we can access the element of an array by considering the array name as pointer. *(a+2) will access the third element of an array a i.e. a[3]. but we can't achieve it by applying ++ operator 3 times since the array pointer can't be modified.


What is an array variable?

An array is a variable containing multiple values. Any variable may be used as an array. There is no maximum limit to the size of an array, nor any requirement that member variables be indexed or assigned contiguously. Arrays are zero-based: the first element is indexed with the number 0.


What does array in mat?

In Mathematics, an array is an arrangement of quantities or symbols in rows and columns; a matrix. In Computing, an array is an indexed set of related elements.


What is the difference between array of pointers and pointer to an array?

An array of pointers is that for eg if we have array of 10 int pointers ie int *a[10] then each element that which is stored in array are pointed by pointers. here we will have ten pointers. In pointer to an array for eg int(*a)[10] here all the elements that is all the ten elements are pointed by a single pointer.


Why does array index start with zero in C language?

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Can an array of pointers represent multidimensional array?

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Difference between pointer and array?

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What is the difference between array and pointer in C?

--> Array is a collection of same kind of data.--> Pointer is a memory location where the data stored in the memory


How do you convert from array notation to pointer notation?

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What is the base address of an array in c program?

the address of variable (pointer) that contains array


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