Answers for "operator keyword c++"

c++ .* operator

The .* operator is used to dereference pointers to class members.

operator c++

Common operators
assignment | increment | arithmetic |  logical | comparison | member | other
		   | decrement |            |		   |		    | access |
-----------------------------------------------------------------------------                            
  a = b    |    ++a    |     +a	    |	 !a	   |   a == b   |  a[b]  | a(...)
  a += b   |	--a	   |     -a		|  a && b  |   a != b   |   *a   |  a, b
  a -= b   |	a++	   |   a + b	|  a || b  |   a < b    |   &a   |  ? :
  a *= b   |	a--	   |   a - b	|	       |   a > b    |  a->b  |
  a /= b   |		   |   a * b	|	       |   a <= b	|  a.b   |
  a %= b   |		   |   a / b	|		   |   a >= b	|  a->*b |
  a &= b   |		   |   a % b	|		   |   a <=> b	|  a.*b  |
  a |= b   |		   |     ~a		|		   |		    |		 |
  a ^= b   |		   |   a & b	|		   |   		    |		 |
  a <<= b  |		   |   a | b	|		   |			|		 |
  a >>= b  |		   |   a ^ b	|		   |			|		 |     
   		   |		   |   a << b	|		   |			|		 |  
     	   |		   |   a >> b	|		   |			|		 |

operators c++

// Operators are simply functions but cooler
// E.g: The + sign is an operator, [] is an operator, you get the point
// Which is even cooler is you can overload them
// Means you can change their behavior
// I can make + actually decrement (dont do this)
int operator+(int other){
	return *this - other;
}
// And make - return always 0
int operator-(int other){ return 0; }
// (THIS IS ANOTHER PROGRAM SO + AND - ARE NOT BROKEN ANYMORE)
#include <iostream>
#include <string>
#include <stdio.h>
#include <vector>
// And then im gonna make a class
class UselessClass{
private:
  	// And have a vector of integers with a bunch of numbers
  	std::vector<int> numbers = {1, 2, 3};
public:
  	// Then im gonna make the array index operator return the int at the index but with 5 added to the int
  	int operator[](int index){
    	return this->numbers[index] + 5;
    }
};
int main(){
    // And then
    UselessClass a;
    std::cout << a[0] << "n";
    // It will print 6
}