/*** * CONTENT: C++ POINTERS - Quick Explanation - WHY *p ? * AUTHOR: RONALDO PI MA SI. * DATE: 2019/07/09. * LANGUAGE: C++. * PLATAFORM: Code Playground SoloLearn. ***/ #include using namespace std; int main() { // Declarate a var as an int, with value 50: int a_number = 50; // It says to compiler: Make a var (allocates a space on memory) to save INT-NUMBER only, // and names this space-of-memory as "a_number", then compiler saves 50 inside that space of memory called "a_number". // Declarative statement for "p" as a pointer, without value for a while: int *p; // It says to the compiler: Make a var (allocates a space on memory) to save ADRESSES-of-INTs-vars only, // and names this space-of-var as "p", We'll can to save ADDRESS-of-INT-vars, only, inside "p", because it is a pointer of int. // Assignment statement for "p": p = &a_number; // It says to compiler: Save (only)the adress of the var-called "a_number" inside that var called "p". // It will be save an hexadecimal address, something like 0x246ab, inside "p", will not be save the a_numbers's value/content 50. // Printing statement: cout << p << endl ; // Print an address saved inside "p". Example 0x246ab. cout << *p << endl ; // Print the integer-50, which was saved inside that adress above, for example. // Math expression statement: cout << 50 << endl ; // Print the value 50. (a simple int). cout << a_number << endl ; // It says to the compiler: print the content saf cout << 10 * 50 << endl ; // Print 500. cout << 10 * *p << endl ; // Also print 500, bacause "*p" take the compiler in a space of memory with "50" saved within. //cout << 10 * p ; // Error, because C++ cannot operate 10 * address (example 0x246ab). cout << "\n\nDid You like it? Please +1 it. \n\n\n"; return 0; }