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References and Dereferences
Pyyhkäise näyttääksesi valikon
Pointers are built around two operators:
- The address-of operator
&. - The dereference operator
*.
Address-of Operator
The address-of operator, represented by &, allows us to directly interact with our computer's RAM. Using & lets you obtain the actual memory address of an object.
Main.c
123456789101112#include <stdio.h> int main() { int x = 100; printf("Value of variable: %d\n", x); printf("Address of variable into RAM: %p\n", &x); // using reference operator `&` for getting address return 0; }
The format specifier used to print addresses (pointers) is %p.
Addresses are typically expressed in hexadecimal notation.
Dereference Operator
Conversely, the * operator gives you the resident's name when given their address. So, how can we employ this operator if we're not directly dealing with addresses? If you have an expression like &x, which returns the address of the x variable, applying the * operator to it (*&x) gives you the value of the variable stored at that address.
Essentially, *&x is the same as x.
Main.c
1234567891011121314#include <stdio.h> int main() { int x = 100; printf("Value of variable: %d\n", x); printf("Address of variable in RAM: %p\n", &x); // using reference operator `&` printf("Dereferencing address of variable: %d", *(&x)); // using dereference operator `*` return 0; }
Don't mix up the dereference operator (*x) with the multiplication operator (x*y).
Pyyhkäise aloittaaksesi koodauksen
- Create an integer array of 5 elements and populate it.
- Retrieve the address of the third element.
- Increment the address of the third element and dereference the incremented address to print the value it points to.
Ratkaisu
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