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Explain the concept of pointer accessing in C language
Pointer is a variable which stores the address of other variable.
Pointer declaration, initialization and accessing
Consider the following statement −
int qty = 179;
Declaring a pointer
int *p;
‘p’ is a pointer variable that holds the address of another integer variable.
Initialization of a pointer
Address operator (&) is used to initialize a pointer variable.
int qty = 175; int *p; p= &qty;
Let’s consider an example how the pointer is useful in accessing the elements in an array of string.
In this program, we are trying to access an element which is present at particular location. The location can be found by using an operation.
By adding pre incremented pointer to pre incremented pointer string and the subtracting 32, you get the value at that location.
Example
#include<stdio.h>
int main(){
char s[] = {'a', 'b', 'c', '
', 'c', '\0'};
char *p, *str, *str1;
p = &s[3];
str = p;
str1 = s;
printf("%d", ++*p + ++*str1-32);
return 0;
}Output
77
Explanation
p = &s[3]. i.e p = address of '
'; str = p; i.e str = address of p; str1 = s; str1 = address of 'a'; printf ("%d", ++*p + ++*str1 - 32); i.e printf("%d", ++
+ a -32); i.e printf("%d", 12 + 97 -32); i.e printf("%d", 12 + 65); i.e printf("%d", 77); Thus 77 is outputted
Updated on: 09-Mar-2021
4K+ Views
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